( 1. 中南大學(xué) 材料科學(xué)與工程學(xué)院， 長(zhǎng)沙 410083;
2. 福州大學(xué) 機(jī)械工程學(xué)院， 福州 350002)
摘 要: 采用XD法原位合成TiCp/Al預(yù)制塊, 并通過(guò)XRD、 SEM、 EDAX和DTA等手段研究了預(yù)制塊的組織和性能， 探討了TiCp/Al預(yù)制塊在鎂液中的熔化行為。 結(jié)果表明： TiCp/Al預(yù)制塊中， 基體Al的熔點(diǎn)約為635.7 ℃， 略低于純鋁的熔點(diǎn)， 但TiC粒子之間存在較強(qiáng)的結(jié)合力， 使其在高溫加熱時(shí)仍能保持原有形狀； 未攪拌時(shí)， TiCp/Al預(yù)制塊在800 ℃的鎂液中保溫60 min后仍不熔化， 采用攪拌工藝有利于促進(jìn)TiCp/Al預(yù)制塊的熔化， 并且使TiC粒子在熔體中均勻分布。 TiCp/Al預(yù)制塊在鎂液中熔化時(shí)， 基體Al通過(guò)熔化和對(duì)流擴(kuò)散進(jìn)入到鎂液中， TiC粒子間的較強(qiáng)的結(jié)合力需通過(guò)攪拌產(chǎn)生的剪切力才能破壞， 并隨鎂液流動(dòng)進(jìn)入到鎂液中。 機(jī)械攪拌可使TiC粒子在鎂液中均勻分布。
關(guān)鍵字: 鎂基復(fù)合材料； TiCp/Al預(yù)制塊； 熔化行為； 原位合成
CHEN Hong-ling2
（ 1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. School of Mechanical Engineering, Fuzhou University, Fuzhou 350002, China）
Abstract: TiCp/Al prefabricating alloy was fabricated by in situ reaction, and its microstructure and mechanical properties were investigated by means of XRD, SEM, EDAX, DTA etc. It is found that the melting point of Al matrix in TiCp/Al prefabricating alloy is about 635 ℃, which is lower than that of pure Al, but there exists a kind of stronger combinational force between TiC particles, which makes the TiCp/Al prefabricating alloy keep its shape at high temperature of 800 ℃. The TiCp/Al prefabricating alloy is melted in molten Mg with different technologies. The results show that the TiCp/Al prefabricating alloy will not be melted after holding for 60 min at 800 ℃ without mechanical stirring; on the other hand, by means of mechanical stirring it can be melted in molten Mg, and therefore makes TiC distribute uniformly in molten Mg. The melting mechanism of the TiCp/Al prefabricating alloy in molten Mg can be explained as follows: with the help of shear force of molten alloy flow produced by mechanical stirring, the combinational force between TiC particles will be destroyed, and therefore, the particles can easily distribute uniformly into the molten Mg.
Key words: Mg matrix composite; TiCp/Al prefabricating alloy; melting behavior; in-situ synthesis
