Study On Microstructure And Friction And Wear Properties Of Hard Phase Reinforced W-Cu Composites

Guiding equipment has a great impact on the production efficiency and quality of iron and steel products,but the existing guiding materials can't meet the requirements of high temperature and high friction service environment.In this study,TiCN/W-Cu composite and TaC/W-Cu composite were prepared by SPS sintering technology using self-made copper-plated tungsten powder and hard phase particles.Their microstructure,mechanical properties and friction,and wear characteristics were studied.We expect that they can meet the requirements of the wear resistance of guide materialsCu@W powder with better coating effect was prepared by electroless plating method.The SPS sintering process of TiCN/W-Cu-Ni composites was optimized,and the sintering temperature of 1200? was determined.TiCN can improve the density and hardness of tungsten-copper composites.The optimal TiCN dosage was 1.5wt.%,the density was 97.9%,and the hardness was 282.7 HV.Appropriate addition amount of TiCN particles can pin the dislocation and crack to obtain dense and uniform structure,improve the density and hardness,but excessive amount of TiCN particles will gather,which is not conducive to densification and sintering.Compared with Ni,TiCN/W-Cu composites with Co addition have higher density and hardness.The SPS sintering process of TaC/W-Cu-Ni composites was optimized,and the sintering temperature was 1200?.TaC can improve the density and hardness of tungsten-copper composites,and the improvement of TaC is more significant than that of TiCN.The optimal TaC dosage was 1.5wt.%,the optimal density was 98.6%,and the hardness was 321.6 HV.An appropriate amount of TaC particles is beneficial to obtain dense and uniform microstructure,improve the density and hardness,but too much TaC particles is not conducive to densification and sintering.Compared with Ni,the density and hardness of TaC/W-Cu composites with Co addition are higher.TiCN/W-Cu-Ni composites have better wear resistance at normal temperature and high temperature than W-Cu-Ni composites.The wear rate of TiCN/W-Cu-Ni composites is lower than that of W-Cu-Ni composites at all temperatures.The wear rate of TiCN/W-Cu-Ni composites is 33.8% lower at 25? and 61.9% lower at 800?.On the one hand,the former has higher matrix strength and can better resist plastic deformation;on the other hand,the copper lubrication film and hard friction layer produced on the surface of TiCN/W-Cu-Ni composites play a wear-resistant and friction-reducing role in the process of high temperature wear.The wear mechanism of TiCN/W-Cu-Ni composites is mainly abrasive wear.With the increase of temperature,fatigue wear,adhesion wear and oxidation wear gradually appear.The wear resistance of TaC/W-Cu-Ni composites is better than that of W-Cu-Ni and TiCN/W-Cu-Ni composites.Compared with W-Cu-Ni and Ti NC/W-Cu-Ni composites,the wear rate of TaC/W-Cu-Ni composites at 25? is 80% and 69.8% lower,the wear rate at 800? is 70.4% and 22.5% lower,and the friction coefficient at 800? is 40.9% and 35% lower,respectively.TaC/W-Cu-Ni composite friction and wear performance is better than that of TiCN/W-Cu-Ni composite materials,in addition to the former has higher concrete strength,but also copper lubrication film and hard friction layer of TiCN/W-Cu-Ni composites are exist at the same time,the synergy produced excellent antifriction abrasion resistance.However,the copper lubrication film and hard friction layer of TiCN /W-Cu-Ni composite alternately act separately.The wear mechanism of TaC/W-Cu-Ni composites is mainly abrasive wear and fatigue wear.With the increase of temperature,adhesion wear and oxidation wear gradually appear.