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RESEARCH OF Co LOSS OF cemented carbides PROGRESSIVE DIE IN HIGH-SPEED STAMPING

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RESEARCH OF Co LOSS OF CEMENTED CARBIDES PROGRESSIVE DIE IN ...

RESEARCH OF Co LOSS OF cemented carbides PROGRESSIVE DIE IN HIGH-SPEED STAMPING

2006年中国机械工程学会年会暨中国工程院机械与运载工...

作者： HUANG Zhenyuan, ZHOU Chi, GUO Lei, RUAN Feng School of mechanical Engineering, South China Univ. of Tech., Guangzhou, Guangdong, 510640, China

Die wear, especial progressive die wear is a major concern in the stamping industry in respect that it brings many problems, including shortened service life, wasted energy, increased production cost

关键词： Die wear progressive die high-speed stamping cemented carbides Co loss.

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RESEARCH OF Co LOSS OF CEMENTED CARBIDES PROGRESSIVE DIE IN ...

The effect of binder phase content on WC-AlCoCrFeNiTi_(0.2) high entropy cemented carbides microstructure and mechanical properties

International Technology and Innovation Conference 2006

作者： HUANG Zhenyuan ZHOU Chi GUO Lei RUAN Feng School of mechanical Engineering South China Univ. of Tech. Guangzhou 510640 China

＜正＞Die wear, especial progressive die wear is a major concern in the stamping industry in respect that it brings many problems, including shortened service life, wasted energy, increased production cost and lowered production efficiency. Alleviating die wear can increase the die inserts’ service life and is helpful to avoid frequent replacement of worn inserts and hence reducing the corresponding costs. WC-Co cemented carbide has good wear resistance and flexibility and is the most common used material for making progressive dies, but the die wear is still a prominent problem, especially in high-speed stamping. Some researches have shown that the appropriate content and even distribution of Co phase are very important to the performance of WC-Co cemented carbides. This paper is conducted to investigate the wear status and mechanism of WC-Co cemented carbides progressive die in high speed stamping. At first, the high-speed stamping test for WC-Co cemented carbides progressive die is carried out to get worn samples. Then the tool microscope is used to observe the surface pattern of the worn cutting edge of the tools. The scanning electron microscope is used to analysis the difference of microstructure of cutting edge of the progressive die both in unworn region and in worn region. The energy spectrometer is used to detect the relative percentage composition of Co and W elements on the cutting edge surface of the progressive die. The results showed that :（1）The macro and micro structure of cemented carbides progressive die change after long time and high speed stamping. （2） There are some small macro pits on the worn cutting edge. （3） The percentage composition of Co element in the worn region decreases. Finally, the Skeleton Theory and Composite Reinforcing Theory are used to analysis the effect of the Co loss. The research shows that the Co loss of cemented carbides in high-speed stamping is an important factor affecting the wearing and property of progressive die.

关键词： Die wear progressive die high-speed stamping cemented carbides Co loss.

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Research and Application of Materials Science 2022年第2期4卷 10-15页

作者： Yuxin WEN Mingchen ZHANG Yong ZHANG State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Inspection and Certification Co. Ltd.MCCBeijing 100088China

Thiswork aims to explore WC-G201 high entropy cemented carbides properties fabricated by spark plasma sintering with AlCoCrFeNiTi_(0.2)and WC as binder phase and hard phase ***_(0.2)powder and WC powder were mixed at the mass ratio of 5:95,10:90 and 15:85 respectively,and then via SPS at 1300℃for *** results show that the binder phase has good wettability to WC,and with the increase of binder phase content,the hardness of the alloy decreases gradually,fracture toughness increases first and then decreases,the maximum value is 7.88 MPa m1/*** is estimated that the comprehensive mechanical property of cemented carbides is the best when the binder content is between 5wt%and 10wt%.

关键词： High entropy alloys cemented carbides binder phase

A new model for thermal conductivity of“continuous matrix/dispersed and separated 3D-particles”type composite materials and its application to WC-M(M=Co,Ag)systems

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Journal of Materials Science & Technology 2022年第2期97卷 123-133页

作者： Shiyi Wen Yong Du Jing Tan Yuling Liu Peng Zhou Jianzhan Long George Kaptay State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Hunan Provincial Key Defense Laboratory of High Temperature Wear-Resisting Materials and Preparation Technology Hunan University of Science and TechnologyXiangtan 411201China State Key Laboratory of cemented Carbide Zhuzhou 412000China University of Miskolc MiskolcEgyetemváros3515Hungary

In the present work a new thermal conductivity model is developed for two-phase composite materials,which are consisted of a continuous matrix and dispersed 3 D-particles separated from each other by the matrix as a function of grain size and volume ratio of the dispersed particles at different *** model is applied to reproduce experimental thermal conductivity values of cemented carbide systems WC-Co and *** agreement was found between measured thermal conductivity data originating from both this work and recent literature and the calculated ones only using semi-empirical parameters for the interfacial thermal resistance(ITR)values at WC/Co,WC/Ag and WC/WC interfaces as a function of ***,the temperature and grain size dependence of the thermal conductivity for WC is established for the first *** model works well for the case when the matrix(Ag)has a higher thermal conductivity compared to that of the WC particles and also for the case when the matrix(Co)has a lower thermal conductivity compared to that of the WC *** new model forms a physically sound basis for further development/materials design of cemented carbides and particlereinforced composite materials.

关键词： Thermal conductivity WC-Co WC-Ag Modeling cemented carbides Composite materials

Effects of nano-Al_2O_3 and nano-ZrO_2 on the microstructure, behavior and abrasive wear resistance of WC-8Co cemented carbide

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Rare Metals 2011年第5期30卷 533-538页

作者： YANG Tian＇en XIONG Ji SUN Lan GUO Zhixing QIN Kangcai School of Manufacturing Science and Engineering Sichuan University Chengdu 610065 China

WC-8wt.%Co cemented carbides with varied nano-Al2O3 and nano-ZrO2 contents were prepared respectively following conventional powder metallurgical procedures. Effects of nano-Al2O3 and nano-ZrO2 on the microstructure, behavior, and abrasive wear resistance were investigated. The result shows that a finer and more homogenous microstructure can be achieved by increasing nano-Al2O3, and increasing nano-ZrO2 makes the microstructure more refined. Nano-Al2O3 and nano-ZrO2 could both help to give increased hardness. Transverse rupture strength is higher if the above nano-oxides are doped appropriately, whereas excess addition is deleterious. Abrasive wear resistance presents different variations with respect to increasing nano-Al2O3 and nano-ZrO2. By contrast, increasing nano-ZrO2 enhances the abrasive wear resistance more effectively than increasing nano-Al2O3. The influence of the two nano-oxides contents on the abrasive wear resistance does not almost vary with wear time, and the optimum addition level of nano-Al2O3 in WC-8%Co cemented carbide is 0.3 wt.% from the stand of abrasive wear resistance. In addition, both of the nano-oxides can retard the increase of wear rate in long-term abrasive wear.

关键词： cemented carbides microstructure abrasion wear resistance oxides mechanical properties

Microstructure and mechanical properties of(Ti,Al,Zr)N/(Ti,Al,Zr,Cr)N films on cemented carbide substrates

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International Journal of Minerals,Metallurgy and Materials 2014年第1期21卷 77-81页

作者： Shi-lu Zhao Jun Zhang Zhen Zhang Shuang-hong Wang Zheng-gui Zhang School of Mechanical Engineering Shenyang University Key Laboratory for Advanced Materials Preparation Technology of Liaoning Province Shenyang University Paint Shop BMW Brilliance Automotive Ltd.

（Ti,Al,Zr）N/（Ti,Al,Zr,Cr）N bilayer films were deposited on cemented carbide （WC-8%Co） substrates by multi-arc ion plating （MAIP） using two Ti-AI-Zr alloy targets and one pure Cr target. To investigate the composition, morphology, and crystalline structure of the bilayer films, a number of complementary methods of elemental and structural analysis were used, namely, scanning electron microscopy （SEM）, energy disperse X-ray spectroscopy （EDS）, and X-ray diffraction （XRD）. Adhesive strength and mechanical properties of the films were evaluated by scratch testing and Vickers microindentation, respectively. It is shown that the resulting films have a TiN-type face-centered cubic （FCC） structure. The films exhibit fully dense, uniform, and columnar morphology. Furthermore, as the bias voltages vary from -50 to -200 V, the microhardness （max. Hv001 4100） and adhesive strength （max. 〉 200 N） of the bilayer films are superior to those of the （Ti,Al,Zr）N and （Ti,Al,Zr, Cr）N monolayer films.

关键词： nitrides thin films cemented carbides microstructure mechanical properties

Rheologic behavior and PIM processing of WC-TiC-Co powder feedstock

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Journal of University of Science and Technology Beijing 2004年第4期11卷 334-337页

作者： XuanhuiQu JianxiangGao MingliQin ChangmingLei BeijingKeyLaboratoryforAdvancedPowderMetallurgyandParticulateMaterials UniversityofScienceandTechnologyBeijingBeijing100083China StateKeyLaboratoryforPowderMetallurgy CentralSouthUniversityChangsha410083China

An improved wax-based binder was developed for the powder injection molding(PIM) of WC-TiC-Co cemented carbides. The critical powder loading and the rheologic behavior of thefeedstock were determined. It was found that the critical powder loading could achieve up to 62.5percent (volume fraction) and the feedstock exhibited a pseudo-plastic flow behavior. The injectionmolding, debinding and sintering processes were studied. The dimension deviation of the sinteredsamples could be controlled in the range of + -0.2 percent with the optimized processing parametersand the mechanical properties were better than or equivalent to those of the same alloy made byconventional press-sintering process.

关键词： powder injection molding (PIM) cemented carbides binder rheology mechanical properties

Assessment of wear micromechanisms on a laser textured cemented carbide tool during abrasive-like machining by FIB/FESEM

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Friction 2021年第3期9卷 656-664页

作者： Shiqi FANG Dirk BÄHRE Luis LLANES Institute of Production Engineering Saarland UniversitySaarbrücken 66123Germany CIEFMA-Department of Materials Science and Engineering EEBE-Campus Diagonal BesòsUniversitat Politècnica de CatalunyaBarcelona 08019Spain

The combined use of focused ion beam(FIB)milling and field-emission scanning electron microscopy inspection(FESEM)is a unique and successful approach for assessment of near-surface phenomena at specific and selected *** this study,a FIB/FESEM dual-beam platform was implemented to docment and analyze the wear micromechanisms on a laser-surface textured(LST)hardmetal(HM)*** particular,changes in surface and microstructural integrity of the laser-sculptured pyramids(effective cutting microfeatures)were characterized after testing the LST-HM tool against a steel workpiece in a workbench designed to simulate an external honing *** was demonstrated that:(1)laser-surface texturing does not degrade the intrinsic surface integrity and tool effectiveness of HM pyramids;and(2)there exists a correlation between the wear and loading of shaped pyramids at the local ***,the enhanced performance of the laser-textured tool should consider the pyramid geometry aspects rather than the microstructure assemblage of the HM grade used,at least for attempted abrasive applications.

关键词： focused ion beam(FIB) field-emission scanning electron microscopy inspection(FESEM) cemented carbides laser surface texturing abrasive machining processes wear

Effects of(Ti, W)C Addition on the Microstructure and Mechanical Properties of Ultrafine WC–Co Tool Materials Prepared by Spark Plasma Sintering

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Acta Metallurgica Sinica(English Letters) 2020年第6期33卷 892-902页

作者： Boxiang Wang Zhenhua Wang Juntang Yuan Bin Yu School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094China

In this study, powder mixtures containing(Ti, W)C additions(10, 20, 30 and 40 wt%) were prepared and then consolidated at 1200, 1250, 1300 and 1350 °C by spark plasma sintering. The effect of(Ti, W)C additions on the microstructure and mechanical properties of ultrafine WC–Co materials was investigated. The results demonstrate that the(Ti, W)C not only retards the sintering densification but also increases the porosity of sintered samples. The increasing sintering temperature is beneficial to the densification but results in the grain coarsening and the dissolution of W in(Ti, W)C. Moreover, there are no(Ti, W)C grains with obvious core/rim structure in the microstructure. With the(Ti, W)C increasing from 10 to 20 wt%, the hardness increases and fracture toughness changes hardly. However, the hardness and fracture toughness decrease slightly as the(Ti, W)C further increases. The transgranular fracture of(Ti, W)C phases is responsible for the slight reduction in fracture toughness. The sample with 20 wt%(Ti, W)C has high hardness and fracture toughness( HV : 21.3 GPa, KIC: 9.8 MPa m1/2).

关键词： (Ti,W)C cemented carbides Spark plasma sintering Microstructure Mechanical properties