热压烧结反应生成TiB／Ti-4．0Fe-7．3Mo复合材料的组织与性能

Microstructure and Mechanical Properties of Reaction Synthesized TiB/Ti-4.0Fe-7.3Mo Composites by Hot Press Sintering

摘要:

采用机械合金化(MA)的方法将B和FeMo粉末与金属Ti的粉末混合均匀，球磨10h后，真空热压烧结制备原位生成TiB增强Ti-4．0Fe-7．3Mo复合材料。在金相显微镜(OM)下观察，复合材料由TiB增强区与不含TiB的基体所组成。TEM研究表明：增强区足由反应生成的TiB增强的α和β-Ti2相共同组成，在α和β-Ti相交界处分布的TiB不仅尺寸较人，而且数量也较两相内部的TiB多。在α钛中观察到少量的平行于α相板条的特殊TiB的存在。反应生成的TiB呈截面为六边形的针状，与基体的界面清洁、平直匹配良好。复合材料的三点弯曲强度和杨氏模量均随反应生成TiB体积含量的增加而降低。

Abstract:

The mechanical alloying (MA) route was used to mix uniformly boron powder, FeMo powder and titanium powder. The mixed powder was vacuum hot press sintered and TiB was formed in-situ during the process. Typical microstructure of the composites has two kinds of areas under optical microscope (OM): in situ TiB reinforced Ti MMCs and the isolated unprocessed material. TEM investigation of the TiB reinforced composites show that these areas are made up of in situ TiB reinforced and Ti matrix. The size and distribution of in situ TiB are different in boundaries and inner of and Ti phases. Most of the in situ TiB needles are random distributed. The transverse section of the in situ TiB needle is hexagonal. The interface between in situ TiB and the Ti MMCs is clear, flat and sharp without any interfacial reaction. The strength and Youngs modulus of the TiB reinforced TMCs decreased with the increasing of in situ TiB volume content.