TiB_2颗粒增强相原位生成机制的研究进展

TiB2/Al复合材料在结构、耐磨、航空航天领域有着广阔的应用前景。然而,不同制备工艺制备的材料在微观结构和性能方面都存在不同,其对应的生成机制也不尽相同。概述了不同工艺制备TiB2颗粒的生成机制。由于混合盐反应法具有易操作、低成本、易连续化生产等特性,因此重点探讨了其反应机理及存在的问题。针对增强相TiB2颗粒微小表面自由能大、容易聚集形成链条状、造成材料的脆性等缺点,给出了几种改善工艺。

Research Progress in the Formation Mechanism of in Situ TiB2 Reinforcing Particulates

TiB2/Al metal matrix composites has emerged as a most promising composite for structural,wear and aero-astro field applications.However,different prepare procedures result in different microstructural features and mechanical properties,and the formation mechanisms of TiB2 are different.The formation mechanisms of in situ TiB2 in different preparations are summarized.The Flux-halide method is discussed in detail owing to its convenient operation,low cost and possibility for batch scale production.The reinforcing phase TiB2 particles are easy to congregate because of their high surface energy which leads to the chain-like agglomeration.When the chain-like TiB2 exists in the matrix,the product will be in brittleness.Consequently,it is very desirable to eliminate the congregation of TiB2.For this,some optimum processing methods are proposed.