烧结温度对高速钢颗粒增强钛基复合材料组织与性能的影响

Effects of sintering temperature on microstructure and properties of high speed steel particles reinforced titanium matrix composites

以M2型高速钢颗粒为增强体,采用放电等离子烧结技术,在850～1 000℃温度下制备高速钢颗粒增强钛基复合材料,研究烧结温度对复合材料显微组织以及硬度与摩擦性能的影响。结果表明,高速钢颗粒与钛基体的界面过渡层未发现孔洞或Ti-Fe金属间化合物,材料的最高致密度达到96.8%。在850℃的烧结温度下,高速钢颗粒周围析出一层碳化物,随烧结温度升高,碳化物因C的扩散而消失,高速钢颗粒中的W、Mo在高速钢颗粒周围富集。高速钢颗粒与钛基体的界面处硬度较高,1 000℃下钛基体的硬度(HV)达426.9。高速钢颗粒的添加有利于改善钛的摩擦性能,高速钢颗粒增强钛基复合材料的磨损方式以黏着磨损为主。随烧结温度升高,材料的硬度逐渐升高且耐磨性增强。

The high-speed steel particle reinforced titanium matrix composites(HSSP/Ti-based composites)were prepared at 850~1 000℃by spark plasma sintering(SPS)using M2 high-speed steel particles as reinforcements.The effects of sintering temperature on the microstructure,hardness and friction property of the composites were investigated.The results show that no pores or Ti-Fe intermetallic compounds are found in the interfacial transition layer between high-speed steel particles and titanium matrix,and the highest density of composites is 96.8%.A layer of carbide precipitates around the high-speed steel particles is founded at the sintering temperature of 850℃.The carbides disappear due to the diffusion of C phase with increasing sintering temperature.The W and Mo elements in the high-speed steel particles are enriched around the high-speed steel particles.The microhardness of the interface between the high speed steel particle and titanium matrix is relatively higher,and the microhardness of the titanium matrix sintered at 1 000℃can reach 426.9 HV.The addition of high-speed steel particles is beneficial to improve the friction property of titanium.The wear mode of high speed steel particles reinforced titanium matrix composites is dominated by adhesive wear.The microhardness and wear resistance of the material both increase with sintering temperature increases.