微觀組織及力學(xué)性能的影響
(1. 鄭州大學(xué) 物理工程學(xué)院，鄭州 450052；
2. 登封電廠集團(tuán)鋁合金有限公司，登封 452477)
摘 要: 采用K2TiF6和KBF4混合鹽原位反應(yīng)法制備TiB2/Al-7Si復(fù)合材料，利用XRD、SEM、金相顯微鏡、HV硬度測(cè)試和磨損實(shí)驗(yàn)等方法研究了Mg對(duì)復(fù)合材料的微觀組織和力學(xué)性能的影響。結(jié)果表明：反應(yīng)生成的TiB2顆粒平均尺寸約為0.5 μm，材料的硬度和耐磨性隨著TiB2含量的增加而提高；添加1.5%Mg(質(zhì)量分?jǐn)?shù))元素可明顯細(xì)化TiB2顆粒，且使其分布更加均勻，增強(qiáng)TiB2顆粒的彌散強(qiáng)化和細(xì)晶強(qiáng)化效果，復(fù)合材料的硬度和耐磨性顯著改善；過量的Mg元素(3%)會(huì)造成TiB2顆粒細(xì)化效果的下降，但其硬度和耐磨性能繼續(xù)得到改善。
關(guān)鍵字: TiB2/Al-7Si復(fù)合材料；Mg；微觀組織；硬度；力學(xué)性能
in-situ TiB2/Al-7Si composite
YU Huan-wei1, REN Bo1, LIU Shuan-jiang1
（1. College of Physics Engineering, Zhengzhou University, Zhengzhou 450052, China;
2. Deng Dian Ji Tuan Aluminum alloys Co. Ltd., Dengfeng 452477, China）
Abstract:In-situ TiB2/Al-7Si composites were fabricated by K2TiF6 and KBF4 compounds reaction in Al-7Si melt. The effect of Mg on the microstructures and mechanical properties of TiB2/Al-7Si were investigated by using XRD, SEM, optical microscopy, hardness and wear testing techniques. The results show that TiB2 particles with average size of about 0.5 μm are produced. The hardness and wear resistance increase with increasing TiB2 content. Adding about 1.5%Mg in melt restrains the conglobation of the TiB2 particles, which makes the size of TiB2 particle decrease and the distribution of TiB2 particle is more homogeneous. The strengthening effect of TiB2 particles is enhanced and the hardness and wear resistance of composites are obviously improved. The excess Mg decreases the refinement effect of TiB2 particles, but the hardness and wear resistance are improved continuously.
Key words: TiB2/Al-7Si composites; Mg; microstructure; hardness; mechanical properties
