鉴于块状非晶合金(BAAs)的低塑性特征,回顾了利用放电等离子烧结?非晶晶化法制备高性能块状材料的成形技术,即先机械合金化制备钛基多组元非晶合金粉末,然后利用放电等离子烧结在粉末的过冷液相区固结非晶粉末,再利用非晶晶化法使烧结的非晶块体在随后的烧结和热处理过程中晶化析出β-Ti延性相,控制延性相的形貌、尺度和分布,合成以非晶相或β-Ti晶化相为基体的钛基块状非晶复合材料(CBBAAs),研究不同添加或替换组元对TiNbCuNiAl非晶粉末颗粒尺寸、热物性和微观结构的作用,探索了不同烧结参数对合成的CBBAAs微观结构和力学性能的影响规律,揭示合成含晶化相CBBAAs的理论基础和非晶晶化过程中晶粒形核长大的规律,提出并利用"发展的软硬模型"来阐释应力作用下CBBAAs的断裂机理。研究结果提供一种极具前途的粉末冶金复合材料制备方法,该方法能制备尺寸较大、力学性能优异的含晶化相的块状复合材料。
In order to circumvent low plasticity of bulk amorphous alloys(BAAs),a material forming method by coupling spark plasma sintering with crystallization of amorphous phase,fabricating composites based on BAAs(CBBAAs) with excellent mechanical property was reviewed systematically.By appropriate annealing of sintered BAAs prepared from spark plasma sintering in the supercooled liquid region of a mechanically alloyed amorphous powder,crystallized ductile β-Ti phase with controllable grain size,phase morphology and distribution can precipitate from the amorphous phase,and therefore,CBBAAs with a matrix of amorphous phase or crystallized β-Ti phase were obtained.The effect of different additions or substitute elements on the particle size,thermal property and microstructure of TiNbCuNiAl amorphous powder,and the influence of different sintering parameters on the microstructure and mechanical property of fabricated CBBAAs were investigated.The theoretical bases of fabricating crystallized phase-containing CBBAAs,and nucleation and growth mechanism of crystalline phase during the crystallization process were elucidated.The facture mechanism of fabricated CBBAAs under stress was explained based on a proposed "Developed hard-soft model".The results provide a promising method for fabricating large-sized crystallized phase-containing bulk composites with excellent mechanical property by powder metallurgy.