Cemented carbide, known as the "teeth of industry", faces significant performance limitations due to corrosion failure in complex environments. The essence of this corrosion lies in the formation of micro-galvanic cells between hard phases and binder phases due to potential differences, leading to hydrogen evolution corrosion in acidic environments and oxygen reduction corrosion with precipitates in neutral / alkaline environments, which can induce secondary corrosion. Studies show that composition optimization effectively enhances corrosion resistance. Ni-based binder phases exhibit superior acid resistance compared to Co-based ones; high-entropy alloy binder phases achieve synergistic optimization of corrosion resistance and mechanical properties through multicomponent alloying to form dense oxide films; refractory metal elements such as Cr and Mo act as additives to promote passivation film formation, serving as key entry points for composition design; binderless phase systems (e.g., pure WC-based composites) offer higher hardness and better corrosion resistance, providing cobalt-free alternative pathways to address cobalt resource scarcity. These findings provide  theoretical support for developing low-cobalt/cobalt-free cemented carbides and designing materials adaptable to complex working conditions, and have important engineering value for improving the reliability of metal cutting tools and wear resistant components in harsh environments.

Tungsten powder, as an important basic material of tungsten products, is widely used in cemented carbide, electronic packaging, aerospace, military defence, and other cutting-edge fields. In this paper, the main research progress of tungsten powder preparation technology in recent years was reviewed, including hydrogen reduction of tungsten oxide, molten salt electrolysis, high energy ball milling, sol-gel method, and plasma method. At the same time, the element doping method, self-propagating high temperature reduction method, circulating oxygen reduction method, H₂O₂ oxidation hydrothermal crystallization method, and methanol vapor reduction method were briefly summarized. The research on the preparation of tungsten powder for additive manufacturing and electronic grade (5N) tungsten powder was introduced. The advantages and disadvantages of various preparation methods were analyzed, and various preparation methods were longitudinally compared. It is pointed out that the future tungsten powder preparation technology will develop towards the  direction of green, compound, functional, and high performance, so as to provide a reference for the sustainable development and application of tungsten powder preparation technology.

 The phase structure of raw materials is related to the various properties of subsequent products, and its differential characterization is an important quality control indicator. However, in actual production, the structural information related to single-phase single-particle powder often requires multiple fine indicators to be characterized, but  there is a lack of unified quantitative methods, and these structural indicators are not as intuitive as physical property indicators such as Fsss and Hall flow rate, featuring small application. The essential difference in phase structure is the change in the degree of phase crystallization. This article attempted to establish a quantitative indicator of crystallinity by X ray diffraction (XRD) to quantify the phase structure differences of each phase in the multiphase powder system. The peak to-valley ratio indicator was established using the peak shape difference characterization method, and the crystallinity of shell and core phases in coarse-grained tungsten carbide powder of 45-75 μm was evaluated. Two methods were used to establish peak area cutting lines based on whether there are overlapping peak areas in the spectrum, and the peak area ratio was used to quantify the difference in peak shape. The method was simple and easy to implement, which was widely applicable and conducive to product quality monitoring and process adjustment. In addition, to obtain the crystallinity of the core phase of coarse particle powder, a powder blending and solidification polishing preparation method can be established to produce high-density "profile state" powder, and the XRD quantitative analysis results have statistical significance. Compared to the traditional method of pressing and sintering with copper doping, it is easier to operate.

Ball milling process is a key factor affecting the microstructure and properties of cemented carbides. In this paper, two kinds of WC with Fisher sub-sieve size (Fsss) of 4.0 μm and 1.4 μm were selected, and Co and Cr₃C₂ were used as raw materials to prepare WC-6%Co-0.5%Cr₃C₂ (mass fraction) bimodal-grained cemented carbides. The effects of the material addition method and different milling processes on the microstructure and properties of the alloy were studied. The results show that bimodal-grained WC-6%Co-0.5%Cr₃C₂ cemented carbides with excellent strength and toughness and good comprehensive properties can be obtained by a reasonable raw material ratio and suitable ball milling process. After pre grinding Cr₃C₂ for two hours, fine WC and Co powder are added for ball milling of 30 hours. Then, coarse WC is added, and ball milling continues for 24 hours, the alloy prepared by this process has the best properties. The bending strength is 3 010 MPa; the hardness is 1 710HV30, and the fracture toughness is 10.166 MPa·m^1/2. Grain refinement can improve the bending strength of the alloy at certain intervals. The combination of coarse and fine grains in the bimodal-grained cemented carbide increases the phenomenon of transgranular fracture due to the presence of coarse grains, resulting in a certain resistance to crack expansion, and a small number of cracks will bypass the coarse particles during the expansion, resulting in deflection and thus improving the fracture toughness of the alloy. Fine particle clusters coated with coarse particle clusters can significantly improve the fracture toughness of the alloy, but the bending strength will be lower than that of the alloy with uniform grain size due to the uneven grain size distribution.

When employing cemented carbide tools for interrupted cutting operations, the cutting edge often experiences premature failure due to fracture well before reaching the wear failure criteria. Subsequent edge passivation treatment significantly enhances the tools impact resistance and stability, thereby reducing the incidence of tool breakage. This article used cutting tools with different blunt radii r_β of the cutting edge for intermittent turning. Experimental research shows that r_β has a significant impact on the impact resistance of the tools. At low cutting speeds of 70～120 m/min, the main failure mode of cemented carbide tools is tip fracture, and its failure mechanism is as follows: initial cracks initiate at the surface coating, then propagate through the coating structure in a stepped pattern, and finally penetrate to the cemented carbide matrix material, causing macroscopic brittle fracture. When the cutting speed is 140～210 m/min, the main causes of tool failure are thermal fatigue damage and plastic damage caused by mechanical fatigue. A larger blunt radius r_β within a certain range indicates a better impact resistance and a longer lifespan of the tool. Through the analysis of cutting forces in three stages of the cutting process, it is found that at the moment of tool entry and exit, the cutting force increases with the increase in cutting speed, and r_β has a significant impact on the main cutting force F_y and cutting depth resistance F_z during entry. In the continuous cutting stage, r_β has the greatest influence on the feed force F_x and the cutting depth resistance F_z , or in other words, r_β has the greatest influence on the stress and deformation of the cutting layer. Therefore, choosing the appropriate blunt radius of the cutting edge is crucial for improving the smoothness, impact resistance, material quality, and tool life during the cutting process.

Nano-tungsten oxide (WO₃ ) is a transition metal oxide, which has broad application prospects in gas sensors, photocatalysis, energy storage, etc. Due to the scarcity and irreplaceability of tungsten resources, China controls the mining intensity of tungsten resources for resource protection and sustainable development. Recycling tungsten scraps can reduce dependence on primary tungsten ore, which has important economic and environmental implications. In this paper, the preparation of nano-WO₃ for battery material doping with cemented carbide scraps as raw materials was studied, and the effect of alkalinity and MgSO₄ excess coefficient on the removal of Si, as well as that of sodium sulfide excess coefficient on the removal of Mo from sodium tungstate solution was investigated. The effects of initial sodium tungstate concentration, excess coefficient of acid, and feeding speed on the preparation of nano-WO₃ were clarified, and the phase and morphology of nano-WO₃ were analyzed. The structure characterization and electrochemical performance test of the cathode materials doped with nano-WO₃ were carried out. The results show that the removal rates of Si and Mo reach 98.97% and 98.75%, respectively. The crystallinity of nano-WO₃ is high, and its morphology is rice-grained. The nano-WO₃ particles are uniformly distributed in the cathode material, and the first coulombic efficiency is 88.1%. The discharge specific capacity is maintained above 97% after 35 cycles of charge and discharge tests.

 Cemented carbide with low Co content has higher hardness, wear resistance, and corrosion resistance than conventional cemented carbide, and it is widely used in the field of precision machining. In this paper, WC with two kinds of particle sizes was used as raw material, combined with two kinds of grain inhibitors, Cr₃C₂ and VC. WC-3%Co cemented carbide was prepared by a low-pressure sintering process. The effect of WC grain size and grain inhibitor on the microstructure and physical properties of the cemented carbide was studied. The results show that Cr₃C₂ and VC can inhibit WC grain growth, but the addition of VC worsens the microstructure. The obtained material has poor comprehensive performance. Compared to those of the cemented carbide with Fsss = 0.35 μm WC, the grain size and microstructure of the cementedcarbidewithFsss=1.04μmWCaremoresensitivetograininhibitors.VChasamoresignificanteffectontheir micro-structure deterioration. In this paper, ultra-fine cemented carbide with low cobalt content and excellent comprehensivemechanical propertieswas successfullypreparedbyadding1.2%Cr₃C₂ (mass fraction) into thecemented carbidewithFsss=0.35μmWC,withahardnessof2220HV30andbendingstrengthof3490MPa.Inaddition, thispaper studiedtheapplicationofwoodworkingtoolsmadeofWCwithdifferentgrainsizes,showinggoodapplicationpotential.

 The microstructure and mechanical properties of the coating were characterized by means of scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and nano-indentation tester. The effects of the CrAlSiN coating on the high-temperature oxidation property, creep property, and fatigue property of  the GH 80A alloy were also studied. The research shows that the prepared CrAlSiN coating has a smooth surface and a dense cross-section, and it exhibits a single-phase NaCl-type face-centered cubic structure. After the GH 80A alloy is coated with the CrAlSiN coating, it shows good oxidation resistance at 800 ℃. The dense Cr and Al oxide layers formed on the coating surface can effectively prevent the substrate from being further oxidized. When the coating is continuously oxidized at 1 000 ℃, the CrAlSiN coating will undergo a phase transformation and precipitate w-AlN, resulting in a significant diffusion of alloy elements in the substrate into the coating. However, the coating still has a certain anti-oxidant protection effect. In addition, the CrAlSiN coating can effectively improve the creep resistance of the GH 80A alloy at the service temperature of 550 ℃andsignificantly increase the fatigue life of the GH 80A alloy.

 Thechip morphology has a significant impact on the chip removal effect of the indexable drill, which in turn affects the dimensional accuracy and surface quality of the workpiece. Therefore, it is particularly important to study the stability application of chip morphology on indexable drills. In this paper, the insert groove of the indexable drill was optimized by reducing the chip curling radius. Firstly, the orthogonal test scheme was designed by selecting the parameters of the insert groove. Through the simulation results of cutting, it was determined that the key parameters affecting the chip curling radius of the insert were the rake angle of the groove g0 , anti-chip angle q, cutting edge height h, and chip breaking groove depth H. Secondly, the parameters were ranked based on their influence, and the optimal groove parameter combination was obtained as A1 B1 C1 D1 E1 F2 G2 . Finally, verification was conducted through a drilling test. The results show that the chip curling radius can be reduced by 17.9% by adopting the optimal parameter combination, which can improve the cutting efficiency.

Polytetrafluoroethylene (PTFE) has a high dielectric constant and low dielectric loss, which is considered an ideal material for the dielectric layer in high-frequency microwave boards. However, when it is mechanically drilled, it is easy to accumulate heat, resulting in problems such as poor chip removal, serious adhesion of debris, and residual stains on the hole wall, which greatly affects the signal transmission capability and reliability of high-frequency microwave boards. Therefore, this paper innovatively put forward the internal spraying cold air-assisted hole making process (internal cooling for short) and compared the tool debris, chip adhesion, and tool wear when drilling holes for two typical high-frequency microwave boards under the three processes of room temperature, external cooling, and internal cooling. The results show that when processing flat glass fiber ceramic PTFE board, internal cold drilling can effectively improve chip entanglement, but the effect of reducing tool wear is very limited; low temperature medium effectively reduces the plastic deformation of the material in the cutting process, and it is more likely to form a short conical spiral chip under the conditions of external and internal cooling. When processing E-type glass fiber PTFE board, due to the lack of ceramic and other hard filler impact on the tool edge and flank surface, the tool wear under the three processing modes is significantly smaller than that of flat glass fiber ceramic PTFE board; both internal and external cold drilling can effectively reduce the adhesion of chips to the tool to prevent the spiral groove from clogging. In addition, due to the direct and effective role of the low temperature medium in internal cold drilling, it can prevent the resin from reaching the molten state to a maximum extent, so as to avoid the resin adhering to the tool and the surface of the chips. It is found that the internal cold drilling process is more suitable for the microhole processing of E-type glass fiber PTFE boards, which can effectively promote the discharge of chips from the holes and prevent the accumulation and aggregation of chips in the spiral groove of the tool.

Carbon fiber reinforced resin matrix composite (CFRP) has excellent physical and chemical properties, which can replace traditional materials in many fields. The existing forming process is relatively mature, and the development prospects are broad. However, CFRP is a typical difficult-to-process material due to its non-uniformity and anisotropy, so optimizing its processing technology has become a key point in China and abroad. Based on current research progress, this article first provided a brief overview of the composition of CFRP from the perspectives of the carbon fiber reinforcement phase and resin matrix. Then, it summarized the traditional and non-traditional processing methods of CFRP, so as to seek efficient processing techniques. Finally, this article provided prospects for the modification of resin matrix, the improvement of diamond coating performance, and the study of cutting mechanism, which can serve as a reference for researchers in related fields.

With the integration and miniaturization of semiconductor electronic devices, the excellent thermal and electrical conductivity of diamond has made it an ideal material for preparing semiconductor substrates. The polished diamond surface is smoother, which can meet the requirements of semiconductor industry for high precision and high reliability, and has important value and significance in improving the performance of semiconductor equipment, prolonging service life and optimizing thermal management. However, the high hardness, wear resistance, and chemical inertness of diamonds pose significant challenges in their processing. Existing diamond polishing technologies have their own advantages and limitations, creating an urgent need for a polishing technology that achieves a smooth, flat, and low-damage diamond surface while ensuring efficiency. Therefore, this paper reviewed relevant literature in China and abroad on diamond polishing technology, summarizing the principles, advantages, and disadvantages of mechanical polishing (MP), thermochemical polishing (TCP), chemical mechanical polishing (CMP), plasma etching polishing (PEP), laser polishing (LP), and other methods. Future diamond polishing technology should develop in the direction of multi-technology integration, intelligence, precision, and environmental friendliness, thereby expanding the application range of diamond materials.

Electroless plating Ni-P plays an important role in anti-corrosion and other fields due to its good hardness, wear resistance and corrosion resistance, in order to further enhance the corrosion resistance and wear resistance of equipment and parts, W element is added on the basis of Ni-P electroless plating. In this paper, the basic principles and process flow of electroless Ni-W-P alloy technology are reviewed, the preparation process of electroless Ni-W-P alloy is expounded, including pretreatment, plating and post-treatment, the methods to improve the comprehensive properties of electroless Ni-W-P alloy are studied, such as rare earth modification and optimization of plating solution composition, and the application advantages of electroless Ni-W-P alloy in the fields of electronics, electromagnetism and automotive are introduced. The effects of pH, temperature and W content on the performance of the coating were analyzed, and the current sewage treatment problems faced by electroless nickel plating were discussed and treatment methods were proposed. In the future, the performance of electroless plated Ni-W-P alloys will be further improved, such as nanomaterials.

A surface defect detection algorithm for hard alloy roller collars was proposed to reliably and accurately detect small and similar surface defects of different categories on hard alloy roller collars. This algorithm was based on the collected surface image of roller collars, and color space processing was performed on the hard alloy roller collar image to generate a variance saliency map of the color space distribution of the hard alloy roller collar image. The saliency map was input into a multi-scale attention mechanism network model, and edge contour defects were extracted from the saliency map through the pyramid segmentation attention module in the model encoder section. They were combined with internal region defects output by global average pooling, and then surface defect detection results were output through upsampling processing. The test results show that the algorithm has good application effects, generating a saliency map that can present the overall contour structure of the roller collar and the location of defects on the roller collar, providing a reliable basis for subsequent surface defect detection of roller collars. It accurately detects small and similar surface defects of different categories, with an average positioning error of less than 0.018 mm and high detection accuracy.

In order to improve the service life of cemented carbide under complex stress conditions, this paper added a few-layer graphene (FLG) (with 1-3 layers) to WC-Co cemented carbide to improve its wear resistance. According to the characterization results, compared with the graphene-free sample, the addition of 0.05% FLG (mass fraction) increases the density and hardness of the sample by 3.6 percentage points and 101HV30, respectively, and it reduces the friction coefficient and wear depth of the sample by about 0.16 and 90%, respectively. The analysis shows that the reason why FLG can enhance the wear resistance of the sample is that it not only can improve the density and hardness of the sample at the same time but also has lubrication and protection effects. In addition, it can supplement carbon in the sintering process. When the mass fraction of FLG exceeds 0.05%, although the friction coefficient of the sample continues to decrease, the density, hardness, and wear resistance all show a downward trend, mainly because too much graphene will lead to agglomeration, and the performance of the graphene after agglomeration will be reduced, making it difficult to achieve an ideal strengthening effect.

Ultrafine-grained gradient cemented carbide was prepared by low-pressure sintering method using ultrafine WC powder as raw material. The effect of carbon content on the microstructure and properties of the ultrafine-grained gradient cemented carbide was investigated by blending the total carbon content in the pristine powder and using SEM, cobalt magnetometer, coercive magnetometer, hardness tester, and universal testing machine. The results are as follows: WC-7%Co cemented carbide with carbon content of 6.07%, 6.12%, 6.17% and 6.22% does not have any decarburization and carburization phases; the thickness of the alloy gradient layer increases from 47.2 µm to 63.4 µm as the carbon content of the raw powder material rises; the average grain size of WC increases slightly, while the edges of the grain boundaries tend to be flattened out, and the grain boundaries become sharper; the cobalt magnet increases gradually, and the coercive magnetic force gradually decreases. The alloy’s bending strength first decreases and then increases, while the Vickers hardness gradually decreases, and fracture toughness slightly increases. The alloy sample with a carbon content of 6.12% has a bending strength of 2 940 MPa, a hardness of 18 670 MPa, and a fracture toughness of 10.44 MPa·m1/2 , respectively, and the overall performance is excellent.

In view of the easy denitrification of the sintered body and the decomposition of N during the preparation of fine-grained Ti(C, N) - based cermets by vacuum sintering, cermets were prepared by nitrogen partial pressure sintering during the liquid heating, insulation, and cooling phases of Ti(C,N)- based cermets. The influence of the nitrogen filling process on the microstructures and mechanical properties of cermets was investigated. The results show that the sintered body is basically dense when nitrogen atmosphere sintering is carried out during the liquid insulation phase, combined with the liquid cooling phase. There is an obvious gradient structure from the surface to the core. The surface is a gray (Ti,Me)(C, N) solid solution layer rich in W and Mo with a coreless ring structure. Compared with those in vacuum sintering, the bending strength and fracture toughness of cermets sintered in the nitrigen atmosphere do not change much, but its hardness increases by about 10%. The increase in hardness mainly comes from the fact that nitrogen partial pressure sintering inhibits the decomposition and escape of nitrogen in the sintered body, thereby increasing the nitrogen content of the sintered body. In addition, nitrogen atmosphere sintering promotes grain refinement in the core, and the hardness of the sintered body increases due to the fine grain strengthening mechanism.

This study focused on the influence of blade shape on the bending fracture failure of micro-drills with large aspect ratios through a combination of finite element simulation and experimental validation. Firstly, based on the transverse rupture strength theory, the strength parameters of the cemented carbide material were determined. Subsequently, finite element simulation was performed to compare the bending fracture characteristics of micro-drills with large aspect ratios in the blade shapes (double-blade single slot and single-blade single slot) with the same chip space for two conventional parameter settings, and validation experiments were designed. The influence of blade shape on the bending fracture of micro-drills with large aspect ratios was analyzed in terms of bending and breaking force, fracture mode, and drilling breakage rate. Simulation and bending fracture resistance experiments show that the double-blade single slot exhibits higher bending fracture resistance than the single-blade single slot, and the bending resistance is optimal when the slot end is downward. The micro-drills with large aspect ratios in two blade shapes show multiple fragmentations in the bending fracture process, and their fracture failure is mainly related to the stress expansion of internal micro-fractures. In addition, in the drilling experiment, the double-blade single-slot micro-drills do not break after drilling 3 000 holes, while the single-blade single-slot micro-drills break in all cases, which further proves that the double-blade single-slot design has an obvious advantage in reducing breakage rate and expanding life expectancy.

Ultrafine-grained cemented carbide is the main material for manufacturing micro drills used on printed circuit boards (PCBs). Cobalt content in cemented carbides is an important parameter that affects their mechanical properties. Three types of ultrafine-grained carbide micro drills with different cobalt contents and an average grain size of 0.3 µm were prepared. They had the same structural design, with a diameter of 0.3 mm and a flute length of 5.0 mm. The performance of the three types of micro drills in drilling a high Tg (Glass Transition Temperature) PCB under six sets of drilling parameters was tested and evaluated from the aspects of wear, hole position accuracy, and hole wall quality. The results show that lower cobalt content indicates smaller micro drill wear and higher hole position accuracy. The cobalt content has no significant impact on hole wall quality. Appropriately increasing the feed speed will help reduce micro drill wear and improve drilling quality. Excessive feed speed will lead to chipping of cutting edges and serious deterioration of hole wall quality. In general, the 0.3 mm diameter carbide micro drill with a cobalt content of 6% and an average grain size of 0.3 µm has the best drilling performance.

The powder properties, pressing properties, microstructure and properties of WC-8%Co-0.4%VC ultrafine cemented carbide mixture prepared by three groups of slurries with different solid contents were studied. The results show that with the decrease in the solid content of the mixture, the content of fine powder in the mixture increases, and the degree of particle breakage increases. The loose density of the mixture gradually decreases from 3.4 g/cm³ to 2.5 g/cm³ , and the fluidity gradually deteriorates from 32 s to 39 s; the pressing pressure of the mixture PS21 increases from 2 250 N to 4 050 N, and the green compact strength decreases from 5.52 MPa to 2.88 MPa. The decrease in the solid content of the mixture leads to the gradual decrease in the average size and maximum size of vanadium-containing particles in the mixture, from 1.085 µm to 0.523 µm and from 1.627 µm to 0.876 µm, respectively. With the decrease in the solid content of the mixture, the uniformity of the cobalt phase in the alloy gradually decreases. When the solid content is as low as 57%, a cobalt pool of more than 1 µm will be formed, which will reduce the bending strength of the alloy. When the solid content is 64%, the alloy has a uniform distribution of WC grains and cobalt phase at the same time, and the bending strength is the highest, reaching 2 780 MPa. Therefore, adjusting the solid content of the mixture reasonably can effectively control the comprehensive mechanical properties of the alloy.

Nanocrystalline binderless cemented carbides were prepared by traditional powder metallurgy process through vacuum high-temperature sintering and vacuum pre-sintering + hot isostatic pressing. The effects of sintering temperature and sintering pressure on the microstructure and mechanical properties of the cemented carbides were studied by Vickers hardness tester, scanning electron microscope, and wet grinding wheel wear tester. The results show that increasing the sintering temperature leads to abnormal grain growth in the cemented carbides, and increasing the sintering pressure results in a high-density and uniform microstructure. The nanocrystalline binderless cemented carbide prepared by vacuum pre-sintering + hot isostatic pressing has excellent mechanical properties. The hardness is 29.01 GPa; the fracture toughness is 8.2 MPa·m1/2 , and the abrasive wear value is 0.06 cm3 /(105 ·r).

In the forming process of cemented carbide cutting blades, the quality of powder filling in the mold cavity will directly affect the quality of the molded parts. Realizing the dense filling of powder in the mold cavity is the key to improving the quality of powder metallurgy products. In this paper, the filling process of the mold cavity during the preparation of cemented carbide cutting blades was studied by the discrete element method (DEM), and ready-to-press (RTP) materials were used as the research object. The DEM models of RTP particles and the power distribution process were established. The powder distribution process was divided into two stages: blanking and particle filling. The packing density and particle segregation were taken as the evaluation indexes for the powder distribution quality inside the mold cavity. The influence of the physical properties of the powder, the geometric structure of the cavity, and the powder distribution technology on the powder distribution effect was analyzed. The results demonstrate that the particle distribution coefficient, the insertion ratio of the feed tube, and the translation speed of the filling shoe are pivotal factors influencing the packing density of the powder within the mold cavity. Specifically, when the particle distribution coefficient (n) is set to 0.5; the insertion ratio of the feed tube is 50%, and the translation speed of the filling shoe is 100 mm/ s, an optimal particle packing density is achieved. By optimizing the key parameters derived from simulation results, the powder distribution effect is enhanced, offering guidance for practical production.

The influence of tool coatings on the processing performance of 6063 aluminum alloy and aluminum substrate, as well as typical aluminum-based materials, was studied. The friction coefficient of aluminum alloy with different coatings was studied by using a friction and wear testing machine, and the morphology and composition of the wear scars on the surface of the grinding pairs were analyzed. Different kinds of coated drill bits and routers were designed to machine 6063 aluminum alloy plate and 5052 aluminum substrate. Through the testing of drilling and routing performance and the evaluation of machining quality, the processing difficulties and tool failure mechanism of aluminum alloy during drilling and routing were analyzed, and the solutions to high quality and long life for processing typical aluminum-based materials used in consumer electronics and electronic circuits were obtained. The results show that the minimum friction coefficient of hydrogen-free diamond-like coating is about 0.06; the friction coefficient of carbon-based composite coating is about 0.15, and the friction coefficients of cemented carbide, TiSi-based coating, and TiAl-based coating are all greater than 0.6. Hydrogen-free diamond-like coating can effectively inhibit the adhesion of aluminum chips on the drill bits and router, improve the chip removal ability of the tool, and keep the cutting edge sharp during machining. During the drilling process, the problems of the broken micro drill bits, a large amount of burrs on the surface of the hole, and short tool life are solved. Compared with uncoated cemented carbide micro drill bits, the life of the drills is increased by three times. During the routing process, a large amount of burrs on the surface of the slot and poor dimensional stability are solved. After routing an aluminum substrate of 10 m, excellent dimensional accuracy can still be obtained.

The chemical vapor deposition (CVD) Al2O3 coating possesses high hardness, good toughness, as well as excellent wear resistance, heat resistance, oxidation resistance, and chemical stability. It is a cutting tool coating material with excellent comprehensive properties. In this paper, the MT-TiCN /Al2O3 / TiN coatings with (104), (0012), and (012) texture orientations of α -Al2O3 were prepared by CVD. The microstructures, texture orientations, and coating properties were studied by using X-ray diffraction (XRD) and scanning electron microscope (SEM). The experimental results show that the columnar grains of the α-Al2O3 coating with high (0012) texture orientation are more complete. The texture orientation of the α-Al2O3 coating will affect the morphology and texture orientation of the surface TiN. The surface TiN of the α-Al2O3 coating with a high (0012) texture orientation exhibits a high (111) texture orientation. The surface TiN of the α -Al2O3 coating with a (104) texture orientation shows a weak (111) + (331) mixed texture orientation. The surface TiN of the α-Al2O3 coating with a (012) texture orientation presents a weak (220) + (420) mixed texture orientation. The results of the cutting experiment on 42CrMo indicate that the wear resistance of the α-Al2O3 coating with a high (0012) texture orientation is superior to that of the coatings with (104) and (012) texture orientations, mainly manifested in that both the rake face and the flank face of the α-Al2O3 coating with a high (0012) texture orientation have better wear resistance.

Ti(C,N)-based cermet was prepared by high temperature and low pressure sintering in Ar + N2 atmosphere with submicron Ti(C,N), different kinds of ultrafine carbides, ultrafine Co powder, and Ni powder as raw materials. The phase composition and microstructure of Ti(C, N) - based cermet were studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). The Vickers hardness and fracture toughness of the specimens were calculated by the Vickers hardness tester. The results show that the sintering temperature is slightly higher than the traditional temperature due to the increase in the types of carbide components. When the sintering temperature is 1 470 °C, the microstructure distribution of the cermet is uniform, and there is no obvious grain growth. The phase only have (Ti,M)(C,N) (M = W, Mo, Nb, and Ta) solid solution phase and Co + Ni bonding phase. At this time, the hardness and fracture toughness of the specimens match the best (1 730HV10 and 8.02 MPa ∙ m1/2 ). Through the optimization of the sintering process, the cooperative regulation of microstructure and mechanical properties is realized.

Selective laser melting (SLM) technology is currently one of the primary processes for additive manufacturing of WC-Co cemented carbides. However, due to the significant differences in physical properties between the metallic and ceramic phases, obtaining crack-free and pore-free cemented carbide components with high performance through SLM printing remains a significant challenge. This work first investigated the influence of laser power, scanning speed, and hatch spacing on the porosity of the fabricated specimens by using WC-Ti powder, which has a relatively small difference in melting points. On this basis, a function relationship between laser process parameters and the density of the printed parts was established. It was found that the scanning speed had the most significant impact on the density of the fabricated specimens. Moreover, by further synergistically optimizing the laser spot size and powder particle size, the porosity of SLM-printed WC-Co cemented carbides was reduced to 1.5%, and cracks were eliminated. Molecular dynamics simulations were employed to reveal the mechanism by which the optimized matching of laser spot size and powder particle size inhibited the formation of cracks, pores, and other defects in the printed cemented carbides. Based on optimized WCCo composite powder, SLM technology, and subsequent heat treatment conditions, a nearly fully dense cemented carbide cutting insert with a bimodal grain microstructure was fabricated. The insert exhibited a Vickers hardness of (1 300 ± 20) HV30, a bending strength of (1 020 ± 130) MPa, and a compressive strength of (3 520 ± 240) MPa. The overall mechanical properties of this material are comparable to those of sintered cemented carbides with similar compositions and grain sizes, demonstrating promising application prospects.

GH4169D has been widely used in the manufacturing of aero engine blades, and the surface integrity after milling significantly affects the working performance of the blades. The milling experiment of GH4169D high-temperature alloy was carried out to study the influence of different process parameters on the surface integrity after milling. The results show that with the increase in milling speed, the surface roughness of GH4169D high-temperature alloy during milling along width cutting direction first increases and then decreases. The roughness along the width cutting direction increases with the increase in cutting width. Milling speed and cutting depth have a greater impact on microhardness. A large milling speed indicates a weak hardening phenomenon; a larger cutting depth indicates an obvious hardening phenomenon. The residual stress on the surface of GH4169D after milling is tensile stress, and a larger cutting speed indicates a larger residual tensile stress. The same relationship is shared between the residual tensile stress and the feed per tooth. When the milling speed becomes larger, the depth of the surface residual stress gradually becomes larger, and the peak of the residual compressive stress becomes smaller. As the milling width becomes larger, the depth of the maximum residual compressive stress does not change significantly, but the peak changes significantly. ap is within 0.16-0.24 mm, and the surface residual stress changes significantly. The depth of the maximum residual compressive stress increases, and the peak value decreases. The plastically deformed layer becomes thinner with increasing milling speed and thicker with increasing cutting depth.

Cemented carbides are indispensable in modern industry due to their various superior properties, but the contradiction between their hardness and toughness limits further performance improvement. Multi-scale material calculation methods integrate multi-scale theoretical models with key experiments, which ensure the efficient development of new materials and provide scientific support for the strengthening and toughening of cemented carbides. This article introduced theoretical methods such as first-principles calculations, thermodynamic and kinetic calculations, phase field simulations, and finite element simulations and demonstrated effective measures for the synergistic enhancement of strength and toughness in cemented carbides, including binder phase strengthening and toughening (nano-scale phase precipitation), hard phase strengthening and toughening (spinodal decomposition), and microstructure optimization (surface gradient structures and whisker toughening). It also discussed the efficient enhancement of cemented carbide performance through a combination of theoretical design and key experimental validation. Multi-scale material calculation methods can provide a theoretical basis and practical guidance for designing and preparing high-strength and high-toughness cemented carbide materials. In the future, it is necessary to further study the intrinsic mechanisms of material microstructure evolution and its structure-property relationships on this basis, so as to promote innovation and progress in the development of cemented carbide materials.

The deep sea contains abundant key metal mineral resources, and the effective development of deep-sea mineral resources is of great significance for alleviating land resource depletion, ensuring national mineral resource security, and promoting the development of key deep-sea technologies. Based on the overview of international deep-sea mineral resources and the current development status of deep-sea mining technology, this article investigated and analyzed the application requirements of cemented carbide materials in deep-sea mining equipment. By taking the picks of polymetallic sulfide mining vehicles as an example, the specific requirements of deep-sea mining for the performance of cemented carbide materials were discussed. Key technologies for cutting and crushing cemented carbide materials used in deep-sea metal mineral development were proposed, providing a reference for the application and development of cemented carbide materials in deep-sea mining.

Multi-principal-element alloys (MPEAs), including high entropy alloys (HEAs), consist of multiple main elements, altering the design concept of traditional alloys. They exhibit excellent strength-plasticity synergy, corrosion resistance, and high-temperature resistance, providing a flexible and efficient approach to optimizing material performance. In high-performance hard alloys, the concept of high entropy has been significantly applied in both the binder phase and the hard phase. This paper studied multi-principal-element binder and hard phases, focused on the influence of high entropy on the microstructures, strength and toughness control, and service performance of hard alloy materials, and introduced recent progress by the authors. Finally, the development prospects of high-entropy hard alloys were discussed.