INCO-617合金空心球颗粒的制备与力学性能研究

Fabrication and Mechanical Properties of INCO-617 Alloy Hollow Sphere Particles

在1100～1230℃的温度下真空烧结表面涂覆一层由聚乙烯醇粘结剂、合金粉末和分散剂构成的浆料的聚苯乙烯球制得高孔隙率的INCO-617合金空心球颗粒,对不同烧结工艺下制备的空心球颗粒的显微组织和力学性能进行了研究。结果表明,INCO-617合金空心球颗粒的密度随烧结温度的升高和烧结时间的延长而增加,其密度值在1.504～2.113g/cm3之间。烧结温度的升高和烧结时间的延长可以明显减少球壁的残余孔隙,这是空心球颗粒显微硬度和压缩性能提高的主要原因,并且,随着球壁内残余孔隙的降低,空心球颗粒压缩时脆性破坏的倾向被抑制。

Regular structured metallic foams might be prepared by sintering or bonding the hollow sphere particles, which are being attracted more interest for various applications. The properties of the final hollow-sphere metallic foams depend to a large extent on the properties of prefabricated hollow sphere particles. In the paper, the high porosity INCO-617 alloy hollow sphere particles were fabricated by sintering polystyrene spheres coated with a slurry, consisting of the PVA binder, alloy powders and dispersant, at temperature ranging from 1100 ℃ to 1230 ℃ in vacuum. The microstructures and mechanical properties of the hollow sphere particles were investigated under different sintering processes. The results show that the densities of INCO-617 alloy hollow sphere particles, increasing with the increase of sintering temperature and sintering time, range from 1.504 to 2.113 g/cm^3. Increase of sintering temperature and sintering time decreases the residual porosity of sphere wall obviously, which is the main factor to enhance the microhardness and compression properties of hollow sphere particles. Furthermore, with the residual porosity in the sphere wall decreasing, the tendency of hollow spheres toward brittle fracture under compression loading is suppressed.