摘要
采用等离子烧结技术(spark plasma sintering,SPS)制备了不同质量分数TiC颗粒增强的铜基复合材料,研究了不同烧结温度和TiC含量的铜基复合材料的微观结构,考察了TiC含量对铜基复合材料电导率、纳米力学性能、显微硬度、拉伸性能和摩擦学行为的影响。结果表明:850℃烧结得到的TiC/Cu复合材料组织致密,增强体和基质相结合良好。一方面,随着TiC含量的升高,TiC/Cu复合材料中的铜基质相的晶粒不断得到细化,晶界密度升高,导致复合材料的硬度和屈服强度升高。另一方面,TiC含量的增加逐渐导致增强体和基质相的结合界面出现孔隙和裂纹,并成为应力集中和裂纹形成的首选位置,造成复合材料电导率、抗拉强度和伸长率的下降。TiC质量分数为5%~15%时,复合材料的抗拉强度、弹性模量和屈服强度较高,硬度适当,综合力学性能较好。当TiC质量分数超过20%时,TiC/Cu复合材料的屈服强度大幅降低,复合材料断裂机制由韧性断裂转为脆性断裂。TiC增强体显著改善了铜基复合材料的摩擦学性能,摩擦过程中复合材料摩擦因数和磨损量随载荷增大呈线性增加,并随TiC含量的升高呈下降趋势。在TiC质量分数为20%时,复合材料具有最高的耐磨性和最低的摩擦因数,其磨损机制以磨粒磨损为主,且伴随轻微黏着磨损和氧化磨损。
Copper matrix composites reinforced with different mass fractions of TiC particles were prepared by spark plasma sintering(SPS)technology.The microstructures of the copper matrix composites with different sintering temperatures and TiC contents were investigated.The effects of TiC content on the electrical conductivity,nano-mechanical properties,microhardness,tensile properties,and tribological behaviors of the composites were studied.Results show that the TiC/Cu composites obtained by sintering at 850℃have a dense structure,with a good bonding between the reinforcements and the matrix.On the one hand,as the TiC content increases,the grains of the copper matrix phase in the TiC/Cu composites are continuously refined and the grain boundary density increases.This leads to an increase in the hardness and yield strength of the composites.On the other hand,the increase in TiC content gradually leads to the development of pores and cracks at the bonding interface between the reinforcement and matrix.When bearing or transmitting load,the pores and cracks will become the preferred location for stress concentration and crack formation,resulting in a reduction in the conductivity,tensile strength,and elongation of the composite.With TiC content of 5%-15%(mass fraction,the same below),the composites have higher tensile strength,modulus of elasticity and yield strength,appropriate hardness,and better overall mechanical properties.When the TiC content exceeds 20%,the yield strength of TiC/Cu composites decreases significantly and the composite fracture mechanism changes from ductile fracture to brittle fracture.The TiC reinforcements significantly improve the tribological properties of the copper matrix composites.The friction coefficient and wear of the composites during friction increase linearly with increasing load and tend to decrease with increasing TiC content.At a TiC content of 20%,the composite has the highest wear resistance and lowest coefficient of friction.The wear mechanism is dominated by abrasive wear,accom
作者
李雪伍
陈朝鹏
尹艳丽
邢志国
于鹤龙
LI Xuewu;CHEN Zhaopeng;YIN Yanli;XING Zhiguo;YU Helong(School of Mechanical Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;National Key Laboratory for Remanufacturing,Army Academy of Armored Forces,Beijing 100072,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2024年第8期178-188,共11页
Journal of Materials Engineering
基金
国家自然科学基金项目(52075544,52275211)
陕西省创新能力支撑计划科技新星项目(2021KJXX-38)。
关键词
铜基复合材料
放电等离子烧结
微观结构
力学性能
摩擦学行为
copper matrix composites
spark plasma sintering
microstructure
mechanical property
tribo‐logical behavior
