标题：Formation of hypoeutectic microstructure in a rapidly solidified Al-5 wt- percent Sr alloy
作者：Z.-H. Zhang;X.-F. Bian;Y. Wang
作者机构：[Zhang, Z.-H] Key Lab. Liquid Struct./Hered. Mat., Ministry of Education, Shandong University, 73 Jingshi Road, Jinan 250061, China;[ Bian, X.-F] Key 更多
通讯作者地址：[Zhang, ZH]Shandong Univ, Minist Educ, Key Lab Liquid Struct & Hered Mat, 73 Jingshi Rd, Jinan 250061, Peoples R China.
来源：Materials Science and Technology: MST: A publication of the Institute of Metals
摘要：The microstructure and thermal analysis of the melt spun Al -5 wt- percent Sr alloy have been investigated using X-ray diffraction, TEM, and differential scanning calorimetry (DSC). The experimental results show that rapid solidification makes the eutectic composition shift to a higher Sr content exceeding 5 wt- percent Sr. The microstructure of the melt spun Al - 5Sr alloy is hypoeutectic and composed of primary alpha-Al cells and the alpha-Al/Al_4Sr eutectic; quite different from that of the ingot like alloy comprising coarse primary Al_4Sr phase embedded in the eutectic. In the melt spun Al - 5Sr alloy, some areas comprise equiaxed or elongated alpha-Al cells with intercellular irregular alpha-Al/Al_4Sr eutectic. Moreover, some areas fully comprise coupled alpha-Al/Al_4Sr eutectic. The eutectic Al_4Sr phase is lamellar strip like or vermiform in morphology. The size of the eutectic Al_4Sr phase is less than 50 nm in width. Furthermore, the very fine microstructure of the melt spun Al - 5Sr alloy has a marked effect on the DSC trace in heating process.