鑄態(tài)組織和凝固行為的影響
(1. 重慶工學(xué)院 材料科學(xué)與工程學(xué)院，重慶 400050；
2. 重慶大學(xué) 材料科學(xué)與工程學(xué)院，重慶 400030)
摘 要: 研究了Zn與Al質(zhì)量比對Mg-Zn-Al三元鎂合金鑄態(tài)組織和凝固行為的影響。結(jié)果表明：Zn與Al質(zhì)量比小于2的實(shí)驗(yàn)合金主要由α-Mg+Mg32(Al, Zn)49相組成，且隨著Zn與Al質(zhì)量比的增加，實(shí)驗(yàn)合金中第二相的數(shù)量逐漸減少，同時(shí)其分布由連續(xù)網(wǎng)狀逐漸向斷續(xù)狀轉(zhuǎn)變；Zn與Al質(zhì)量比大于2的實(shí)驗(yàn)合金則主要由α-Mg+Mg32(Al, Zn)49+MgZn相組成，且隨著Zn與Al質(zhì)量比的增加，實(shí)驗(yàn)合金中第二相的數(shù)量逐漸增加，同時(shí)其分布由斷續(xù)網(wǎng)狀逐漸向顆粒彌散狀轉(zhuǎn)變；此外，Zn與Al質(zhì)量比小于2的實(shí)驗(yàn)合金的第二相轉(zhuǎn)變開始溫度和峰值溫度基本上高于Zn與Al質(zhì)量比大于2的實(shí)驗(yàn)合金，從而導(dǎo)致第二相轉(zhuǎn)變過程中不同相變的發(fā)生和第二相類型的不同。
關(guān)鍵字: Mg-Zn-Al鎂合金；鑄態(tài)組織；凝固行為
solidification behaviour of Mg-Zn-Al ternary magnesium alloys
（1. School of Materials Science and Engineering, Chongqing Institute of Technology, Chongqing 400050, China;
2. College of Material Science and Engineering, Chongqing University, Chongqing 400030, China）
Abstract:The effect of mass ratio of Zn to Al on the as-cast microstructure and solidification behaviour of Mg-Zn-Al ternary magnesium alloys was investigated. The results indicate that, when the mass ratio of Zn to Al of experimental alloys are less than 2, the alloys are composed of α-Mg and Mg32(Al, Zn)49 phases, and with increasing mass ratio of Zn to Al, the amount of the second phases in the alloys gradually decreases and the distribution of the second phases changes from continuous net to quasti-continuous net. However, when the mass ratio of Zn to Al of experimental alloys is more than 2, the alloys are composed of α-Mg, Mg32(Al, Zn)49 and MgZn phases, and with increasing mass ratio of Zn to Al, the amount of the second phases in the alloys gradually increases and the distribution of the second phases changes from quasti-continuous net to uniform particles. In addition, the onset and peak temperatures of the second phase transformation for the experimental alloys with relatively low mass ratio of Zn to Al (＜2), are higher than those of the alloys with high mass ratio of Zn to Al (＞2), which results in different reactions during the second phase transformation and different types of the second phases.
Key words: Mg-Zn-Al magnesium alloy; as-cast microstructure; solidification behaviour
