热处理时间对摩擦挤压合金化Ni-Al金属间化合物微结构的影响

Effects of Heat trearment Time on Structure of Friction Extrusion Alloying Ni-Al Internetallic Compound

摩擦挤压合金化方法是制备Ni-Al材料的一种新固态合金化法,但这种方法制备得到的材料组织在稳定性、均匀性和致密性等都存在不足,本文通过研究热处理保温时间,来优化与改善它的组织结构。通过X射线衍射仪、电子显微镜和扫描电镜及能谱分析Ni-Al材料的组织微结构。结果表明:热处理保温时间对摩擦挤压Ni-Al材料的合金化是有益的。在550℃温度下,随着保温时间从3 h到5 h,最后延长至7 h后,Ni-Al材料组织中悬浮的Ni粉末从大团聚到弥散分布,最后消散形成Ni块,并与Al基体在两者界面处形成一层固溶区;另一方面,Ni-Al材料物相由单质Ni和Al到过渡相Al4Ni3,最后形成亚稳相Al3Ni。

Friction extrusion alloying method is a kind of new solid alloying method prepared Ni-Al materi- al, but structure of Ni-Al material preparated compactness, so its structure is optimized paper. Microstructure of Ni-Al material is and by this method exists insufficient in stability, uniformity and improved by studying the heat treatment soaking time in this analyzed by X-ray diffraction, electron microscope and scanning electron microscopy （SEM） and energy spectrum. The results show that the friction heat treatment soaking time is beneficial on the extrusion alloying of Ni-Al material. The suspending Ni powder transforms from big agglomeneration to diffuse distribution, and forms finally Ni piece in structure of Ni-Al material with the soaking time from 3 h to 5 h, eventually extended to 7 h at 550 ℃ and forms a layer of solid solution area at the interface between the Al substrate and Ni piece. On the other hand, phase of Ni-Al material is from elementary substance Ni and Al to the transition phase Al4Ni3, and forms finally a metastable phase Al3Ni.