HfC颗粒增强NiAl基纳米复合材料的机械合金化与力学性能

Mechanically Synthesis and Mechanical Properties of Nanocrystalline NiAl Matrix Composite Reinforced by HfC Particles

球磨 Ni,Al,Hf,C元素粉末反应合成 Ni Al- Hf C复合材料 ,形成机制归结为机械碰撞诱发的双爆炸反应 (Ni+Al→Ni Al+△H;Hf+C→ Hf C+△ H)。采用热压和热等静压工艺将纳米粉末压制成较密实的块体材料 ,进而研究其微观组织与力学性能。结果表明反应球磨制备的 Ni Al- 10 Hf C复合材料中强化相细小弥散 ;较大的颗粒 (5 0～10 0 nm)一般分布于晶界。恒应变速率压缩其室温至高温屈服强度均显著高于 Ni Al,且具备较好的高温塑性 ;材料的高温强度依赖于应变速率 。

WT5BZ]Reactive milling elemental mixed powders have been used to synthesize NiAl HfC composite The formation mechanism can be attributed to two explosive reaction, Ni+Al→NiAl+△H; Hf+C→HfC+△H, aroused by mechanical collision After densification by hot pressing and isostatically pressing, its microstructure and mechanical properties have been investigated The results show that the reinforced HfC particles size is below 100nm, and coarse ones (50~100nm) are distributed mainly in grain boundaries of matrix The yield strength of NiAl 10HfC composite is significantly stronger than that of NiAl Furthermore, it also possesses good compressive ductility The yield strength of NiAl 10HfC composite at high temperature is dependent on strain rate, and deformation is controlled by diffusion mechanism