摘要
针对钛基复合材料中增强相易团聚的问题,采用固溶加时效的热处理工艺对其组织进行优化,研究了Ti3SiC2含量对材料微观组织及力学性能的影响。通过扫描电子显微镜和能谱分析仪观测了不同Ti3SiC2含量的复合材料的微观组织形貌,并探究热处理过程中基体组织的细化机制与增强相的析出规律,进而分析了室温力学性能的变化规律。实验结果表明:随着Ti3SiC2含量的增加,固溶处理后的原始晶粒尺寸大幅度减小,时效处理后的片状α相和团簇组织的平均尺寸也呈递减趋势;Ti5Si3颗粒在β相内、α/β相界处和α相内均有析出,其含量随Ti3SiC2质量分数增加而递增;(Ti5Si3+TiC)/TC4复合材料的屈服强度和抗压强度均明显高于相同热处理条件下的基体TC4合金,当Ti3SiC2的质量分数为8%时,复合材料的屈服强度和抗压强度分别达到1 930 MPa和2 500 MPa,综合力学性能最优;当Ti3SiC2的质量分数继续增加至10%时,复合材料的力学性能难以通过固溶和时效处理进一步改善。
To improve the aggregation of reinforcements in titanium matrix composites,solid solution and aging treatments were used,and the effects of Ti 3SiC 2 content on the microstructure and mechanical properties of the composites were studied.Scanning electron microscope and energy spectrum analyzer were adopted to observe the microstructures with different Ti 3SiC 2 contents.The refining mechanism of the matrix and the precipitation of the reinforcements during the heat treatment were investigated.The results show that the original grain size of as-treated composites decreases significantly with the Ti 3SiC 2 content,and the grain size of lamellaαphase also reduces.Ti 5Si 3 particles precipitate in theαandβphases and at the interface ofαandβphases,and its content increases with Ti 3SiC 2 content.The yield strength and compressive strength of the composites are significantly higher than that of TC4 alloy under the same heat treatment condition.When the mass fraction of Ti 3SiC 2 is 8%,the yield strength and compressive strength of(Ti 5Si 3+TiC)/TC4 composite reach 1930 MPa and 2500 MPa,respectively,and the best comprehensive mechanical properties are obtained.When the mass fraction of Ti 3SiC 2 increases continuously to 10%,the mechanical properties of the composites cannot be further improved through solid-solution strengthening and aging treatment.
作者
王芝萍
高义民
黄孝余
赵四勇
WANG Zhiping;GAO Yimin;HUANG Xiaoyu;ZHAO Siyong(State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an 710049,China;Institute of Foundry Technology and Wear Resistant Materials,Xi’an Jiaotong University,Xi’an 710049,China;Guangxi Great Wall Machineries,Hezhou,Guangxi 542699,China)
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2020年第7期196-204,共9页
Journal of Xi'an Jiaotong University
基金
广东省重点领域研发计划资助项目(2019B010942001)
广西创新驱动发展专项资金资助项目(桂科AA18242001)
广东省科技计划资助项目(2015B010122003)。