创新构型泡沫TiAl的制备及其力学响应特征

Preparation and Mechanical Response Characteristics of TiAl Foam with Innovative Configuration

兼有金属和陶瓷特性的TiAl金属间化合物泡沫材料具有明确的性能优势和目标需求,在高温隔热材料、酸碱环境下的过滤材料、催化剂载体等领域有广阔的应用前景。本文首先采用Ti/Al元素粉末反应烧结制备了TiAl合金粉体,然后采用脱溶-烧结工艺制备了孔隙分布均匀、通孔型单孔结构的泡沫TiAl,该工艺可实现孔隙率、孔径、孔形等可控。准静态压缩测试表明,TiAl属于脆性泡沫材料,超过弹性区到达上屈服点时,材料瞬时坍塌失效。同时,随孔隙率的增大,TiAl的屈服强度、杨氏模量和弹性区域均减小,屈服强度与孔隙率的响应关系满足Gibson-Ashby模型。

There are incontrovertible performance advantage and objective demand for TiAl intermetallic compound foam materials with metal and ceramic properties,which has a wide application prospect in the fields of high temperature insulating material,filter material in acid-base environment,catalyst carrier etc.The TiAl alloy powder in the present study was firstly fabricated using the Ti/Al elemental power sintering.Then the open pore TiAl foam with single structure was prepared using the dissolution-sintering method.The TiAl foam has a well uniform pore distribution and the porosity,pore size and pore shape can be tailored according to the desirable demand.The quasi-static compression was carried out to characterize the mechanical properties of the TiAl foam.It was found that the TiAl foam belongs to typical brittle foam material.However,the TiAl will completely collapsed and become invalid once the compressive stress exceeds the upper yield strength after linear elastic region.Moreover,the yield strength,Young＇s modular,elastic region of the TiAl foam decrease with increasing the porosity.The relationship between yield strength and porosity coincides well with the Gibson-Ashby model.