造孔剂（NH4）2CO3和尿素含量对TiAl多孔材料性能的影响

Effect of pore-forming agent （NH4）2CO3 and urea on properties of porous TiAl intermetallics

以 Ti、Al 元素粉末为原料,分别添加(NH4)2CO3和尿素,利用偏扩散反应,制备高孔隙度,孔特征可控的 TiAl 金属间化合物多孔材料。通过 XRD、SEM、金相显微技术等表征手段,研究造孔剂含量对 TiAl 金属间化合物多孔材料的物相结构、孔径、总孔隙率、透气度、膨胀率及力学性能的影响。结果表明:造孔剂对多孔材料物相组成没有影响;分别添加 7%碳酸铵和尿素后,平均孔径分别对应为 30.6 μm 和 28.8 μm,体积膨胀率增大到45.6%和 44.4%,总孔隙率为 49.9%和 48.3%,透气度为 307.3 m3/(m2 kPa1 h1)和 302.1 m3/(m2 kPa1 h1),极限抗拉强度分别为 27.85 MPa 和 32.49 MPa。

Ti and Al intermetallic compound porous materials with high porosity and controllable pore characteristics were prepared by partial diffusion reaction using Ti and Al powders as raw materials and(NH4)2CO3 and urea as pore formation agent. By means of XRD, SEM and metallographic microscopy, the effects of pore-forming agent content on the phase structure, pore size, total porosity, permeability, expansion rate and mechanical properties of TiAl intermetallic compound porous materials were studied. The results show that the pore-forming agent has no effect on the phase composition of porous materials, and the average pore diameters are 30.6 mm and 28.8 mm respectively with adding 7%ammonium carbonate and urea, the volume expansion rate increases to 45.6% and 44.4%, the total porosity is 49.9% and48.3%, the permeability is 307.3 m3/(m2·kPa1·h1) and 302.1 m3/(m2·kPa1·h1), and the ultimate tensile strength are 27.85 MPa and 32.49 MPa respectively.