Numerical simulation and experimental investigation of Ti-6Al-4V melted by CW fiber laser at different pressures  

作　　者：Aasma Tabassum ZHOU Jie HAN Bing NI Xiao-wu Maryam Sardar Aasma Tabassum;周洁;韩冰;倪晓武;Maryam Sardar(School of Science, Nanjing University of Science and Technology;Advanced Launching Co-innovation Centre, Nanjing University of Science and Technology)

机构地区：[1]School of Science, Nanjing University of Science and Technology, Nanjing Z10094, China [2]Advanced Launching Co-innovation Centre, Nanjing University. of Science and Technology, Nanjing 210094 China

出　　处：《Optoelectronics Letters》2017年第4期299-303,共5页光电子快报（英文版）

基　　金：supported by the National Natural Science Foundation of China for Young Scholars(No.11402120);the Jiangsu Provincial Natural Science Foundation for Young Scholars(No.BK20140796);the Fundamental Research Funds for the Central Universities(No.30915015104)

摘　　要：The interaction of continuous wave （CW） fiber laser with Ti-6A1-4V alloy is investigated numerically and experi- mentally at different laser fluence values and ambient pressures of N2 atmosphere to determine the melting time threshold of Ti-6A1-4V alloy.＇ A 2D-axisymmetric numerical model considering heat transfer and laminar flow is es- tablished to describe the melting process. The simulation results indicate that material melts earlier at lower pressure （8.0 Pa） than at higher pressure （8.8x 104 Pa） in several milliseconds with the same laser fluence. The experimental results demonstrate that the melting time threshold at high laser fluence （above 1.89x 108 W/m2） is shorter for lower pressure （vacuum）, which is consistent with the simulation. While the melting time threshold at low laser fluence （below 1.89x 108 W/m2） is shorter for higher pressure. The possible aspects which can affect the melting process in- clude the increased heat loss induced by the heat conduction between the metal surface and the ambient gas with the increased pressure, and the absorption variation of the coarse surface resulted from the chemical reaction.

关 键 词：Aluminum Fiber lasers Heat conduction Heat transfer Laminar flow MELTING Metal melting Numerical models Ternary alloys Titanium alloys Tungsten alloys Vanadium alloys 

分 类 号：TG665[金属学及工艺—金属切削加工及机床] TN248[电子电信—物理电子学]