粉末冶金制备原位自生钛基复合材料的显微组织和力学性能研究.pdfVIP

学兔兔 第 19卷第3期 粉 末 冶 金 工 业 Vo1．19 No．3 2009年6月 POWDER METALLURGY INDUSTRY Jun．2009 粉末冶金制备原位自生钛基复合材料的显微组织 和力学性能研究 周 鹏，覃继宁，吕维洁，张 荻 (上海交通大学 金属基复合材料国家重点实验室，上海 200240) 摘 要：利用Ti与B C、C、LaB 之间的化学反应，采用粉末冶金工艺制备了原位自生钛基复 合材料(TiB+TiC+LazO。)／Ti一6AI一4V；通过X射线衍射仪和光学显微镜，分析了材料的物 相组成、显微组织及增强体的微观形貌；测试了材料的室温和高温力学性能，并分析了断裂机 理。结果表明：增强体总体分布均匀，但局部有团聚现象，形状和尺寸多样；粉末冶金制备Ti一 6Al一4V的抗拉强度高于铸造工艺制备的材料，增强体的原位合成使复合材料的室温和高温性 能与基体相比明显提高；室温时，体积较大的增强体的断裂是复合材料失效的主要原因，高温 下则主要是增强体和界面的脱粘导致材料失效。 关键词：粉末冶金；钛基复合材料；显微结构；力学性能；断裂机理 中图分类号：TF125．22 文献标识码：A 文章编号：1006—6543(2009)03—001l一06 MICROSTRUCTURE AND MECHANICAL PROPERTIES OF IN—SITU SYNTHESIZED TITANIUM MATRIX COMPOSITES PREPARED BY POWDER METALLURGY ZHOU Peng，QIN Ji-ning，LU Wei-jie。ZHANG Di (State Key Laboratory of Metal Matrix Composites，Shanghai Jiao Tong University，Shanghai 200240-China) Abstract：Titanium alloy matrix composites(TMCs)reinforced with TiB，TiC and La2 O3 were prepared through the synthesis reaction between Ti and B4 C，C，LaB6 by powder metal— lurgy(PM)．The phases were identified by XRD。and the microstructures were examined by optical microscopy(OM)．Tensile properties were tested at room temperature，400℃，450℃ and 500℃，respectively，and the fracture surfaces were examined by scanning electron mi— croscopy(SEM)．The results show the reinforcements were uniformly distributed in the ma— trix alloy as a whole，but locally agglomerated with varied shapes and sizes。Ti一6A1—4V pro— duced by hot—pressing