Competition Growth of α and β Phases in Ti-50 at.%Al Peritectic Alloy during the Rapid Solidification by Laser Melting Technique  

作　　者：Wenjing YAO Xiuling NIU Long ZHOU Nan WANG Jehyun LEE 

机构地区：[1]The Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education, School of Science, Northwestern Polytechnical University [2]Engineering Research Center for Integrated Mechatronics Materials and Components, Changwon National University,92 Toechon-ro, Uichang-gu Changwon-si

出　　处：《Acta Metallurgica Sinica(English Letters)》2013年第5期523-532,共10页金属学报（英文版）

基　　金：supported by the National Natural Science Foundations of China Nos.51271149 and 50901060);the National Basic Research Program of China(No.2011CB610404);the National Aerospace Science Foundation of China(No.2010ZF53059);the NPU Foundations for Fundamental Research(No.NPUJC20110279);the Fund of the Innovation Base of Graduate Students of NPU;supported partly by the National Research Foundation of Korea(No.2012-0009451)

摘　　要：Rapid solidification of Ti-50 at.%Al peritectic alloy is realized by laser melting technique at diferent conditions of laser power and scanning speed. The temperature field and the cooling rate under the corresponding conditions are derived from the finite element simulation.℃omparing the measured pool size with the simulated result, the laser absorptivity of Ti-50 at.%Al peritectic alloy at diferent conditions can be deduced to establish the relationships between the laser absorptivity, the laser power and the scanning speed. The morphology evolution and the phase selection of Ti-50 at.%Al peritectic alloy are described by the temperature gradient and the cooling rate. With the increase of temperature gradient and cooling rate, β phase replaces α phase to become the leading growth phase. And the growth of α phase experiences the transition from facet to non-facet manner, while β phase is refined. To understand the underlying mechanism of the competition growth can bring benefit to the industrial application of Ti-Al alloy.Rapid solidification of Ti-50 at.%Al peritectic alloy is realized by laser melting technique at diferent conditions of laser power and scanning speed. The temperature field and the cooling rate under the corresponding conditions are derived from the finite element simulation.℃omparing the measured pool size with the simulated result, the laser absorptivity of Ti-50 at.%Al peritectic alloy at diferent conditions can be deduced to establish the relationships between the laser absorptivity, the laser power and the scanning speed. The morphology evolution and the phase selection of Ti-50 at.%Al peritectic alloy are described by the temperature gradient and the cooling rate. With the increase of temperature gradient and cooling rate, β phase replaces α phase to become the leading growth phase. And the growth of α phase experiences the transition from facet to non-facet manner, while β phase is refined. To understand the underlying mechanism of the competition growth can bring benefit to the industrial application of Ti-Al alloy.

关 键 词：Rapid solidification Laser melting Competition growth Temperature field 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TN241[金属学及工艺—金属材料]