无压烧结Ti-Al多孔材料的组织结构与反应机制  

Microstructure and Formation Mechanism of Porous Ti-Al Intermetallics Prepared by Pressureless Sintering

作　　者：冯培忠[1] 苏健[1] 周亚国[1] 王建忠[2] 葛渊[2] 刘章生[1] 王晓虹[1] 

机构地区：[1]中国矿业大学,江苏徐州221116 [2]西北有色金属研究院金属多孔材料国家重点实验室,陕西西安710016

出　　处：《稀有金属材料与工程》2015年第11期2721-2727,共7页Rare Metal Materials and Engineering

基　　金：中央高校基本科研业务费专项资金资助项目(2012QNA02);国家自然科学基金资助项目(51202289);金属多孔材料国家重点实验室开放课题基金资助(PMM-SKL-3-2012);"青蓝工程"(苏教师〔2012〕39号)

摘　　要：以Ti和Al 2种粉末为原料,采用粉末压制一无压烧结技术制备了TiAl多孔材料,并对其宏观形貌、相组成、孔结构、反应机制和孔隙形成机理进行了分析。结果表明：Ti-Al粉末压坯在烧结过程中发生了明显的体积膨胀,多孔材料的总孔隙率为49.88%57.53%,开孔率为47.60%56.15%。多孔材料主要由连续的颗粒骨架、骨架之间的大孔隙和骨架内部的小孔隙构成,孔隙主要来自粉末压坯颗粒之间存在的原始大孔隙、无压烧结过程中先熔化的Al颗粒在毛细作用下发生流动形成的原位大孔隙和析出过程在Ti-Al产物颗粒之间形成的小孔隙。Ti-Al多孔材料主要由TiAl3单相构成,无压烧结过程中Ti-Al之间发生了热爆反应。Porous Ti-Al intermetallics materials were prepared form titanium and aluminum powders by pressureless sintering route,and the macro-morphology,phase composition,porosity,microstructure and formation mechanism of porous Ti-Al intermetallics were investigated.The results show that the volume expansion of the Ti-Al compacts is observed in all samples.The porosities of Ti-Al intermetallics are within the range of 49.88%57.53%,and the open porosities are within the range of 47.60%56.15%.The porous materials are made of interconnected skeleton,big pores among skeleton and small pores in the interior of skeleton.The interstitial pores in green powder compacts are the most important source of big pores of porous Ti-Al intermetallics,and the in-situ pores from the melting and flowing of aluminum powders is also significant to the formation of big pores.Small pores are from the precipitation of Ti-Al intermetallics particles in pressureless reactive sintering,and TiAl3 is the main phase of porous materials,and porous Ti-Al intermetallics are formed by thermal explosion mechanism.

关 键 词：多孔材料 金属间化合物 无压烧结 TI Al 

分 类 号：TB383.4[一般工业技术—材料科学与工程]