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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TiAl_3单相构成,无压烧结过程中Ti-Al之间发生了热爆反应。
The TiAl porous materials were prepared by powder pressing and pressureless sintering using Ti and Al powders as raw materials, and the macroscopic morphology, phase composition, pore structure, reaction mechanism and pore formation mechanism were analyzed. The results show that the volume expansion of Ti-Al powder compact during sintering is obvious. The total porosity of porous material is 49.88% -57.53% and the porosity is 47.60% -56.15%. The porous material is mainly composed of continuous particle skeleton, macropores between the skeleton and small pores inside the skeleton. The pores mainly come from the original macropores existing between the powder compact particles. During the pressureless sintering, the Al particles melted in the capillary Under the action of flowing formed in situ large pores and precipitation process in the Ti-Al product particles formed between the small pores. The Ti-Al porous material is mainly composed of TiAl_3 single phase, and the thermal explosion reaction of Ti-Al occurred during pressureless sintering.