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烧结膨胀特性是元素粉末反应合成Ti-Al合金多孔材料的重要特征,与其孔结构性能密切相关。本文在其它制备参数一定的条件下,从普通反应合成和约束烧结二个过程分别论述Ti-Al合金多孔材料的膨胀行为及其规律。结果表明:Ti/Al元素的溶解度和扩散速率的差异导致Kirkendall孔隙的产生,引起了坯体体积的大幅度膨胀。在Al的第一阶段偏扩散过程中,Ti-Al烧结坯发生了高达60%以上的大幅度体积膨胀行为,同时坯体的开孔隙度接近40%;在Al的第二阶段偏扩散过程中,Ti/Al烧结坯的体积膨胀量为1%-3%,同时坯体的开孔隙度达到47%左右。而在约束烧结过程中,Ti-Al合金多孔材料的前期膨胀行为表现出严格的直线变化规律;在烧结后期,Ti-Al合金多孔材料表现出体积略为收缩的行为。
Sintering expansion characteristics of the elemental powder synthesis of Ti-Al alloy porous material important features, and its pore structure properties are closely related. In this paper, under the condition of certain other preparation parameters, the expansion behavior and regularities of Ti-Al alloy porous materials are discussed respectively from the two processes of ordinary reaction synthesis and constrained sintering. The results show that the difference of solubility and diffusion rate of Ti / Al element lead to the formation of Kirkendall pores, causing a large volume expansion of the green body. In the first stage of partial diffusion of Al, the volume expansion behavior of Ti-Al sintered billet was up to 60%, while the open porosity of the billet was close to 40%. During the second phase of Al diffusion , The volume expansion of the Ti / Al sintered billet is 1% -3%, while the open porosity of the billet reaches about 47%. In the restrained sintering process, the pre-expansion behavior of Ti-Al alloy porous material showed a strict linear variation. At the late sintering stage, Ti-Al alloy porous material showed a slightly shrinking volume.