(1. 西安理工大學(xué) 材料科學(xué)與工程學(xué)院，西安 710048；
2. 陜西天成航空材料有限公司，咸陽 712000)
摘 要: 采用CAFE(Cellular automation finite element)對Ti6Al4V合金絲材電弧增材制造的快速凝固過程進行模擬計算。通過建立不同階段(堆積層)的三維模型，建立晶體形核與生長模型，并結(jié)合三維熱傳導(dǎo)(包含結(jié)晶潛熱釋放)模型，研究了不同階段的溫度場對固-液轉(zhuǎn)變、初始β晶形核及生長等影響。結(jié)果表明：初始階段初始β晶取向雜亂且晶粒尺寸細小；隨著增材高度的增加，水平方向溫度梯度變緩，平均固-液轉(zhuǎn)變糊狀區(qū)域?qū)挾仍黾樱跏鸡戮骄Я３叽缭黾樱w取向趨于熱流傳遞方向(垂直于冷基板方向)；其模擬結(jié)果與實際增材制造后的初始β晶組織形貌基本一致。
關(guān)鍵字: CAFE；合金絲材；電弧；增材制造；Ti6Al4V；晶體生長
（1. School of Material Science and Engineering, Xi’an University of Technology, Xi’an 710048, China;
2. Shaanxi Tian Cheng Aerospace Co., LTD., Xianyang 712000, China）
Abstract:CAFE model was adopted to simulate the rapid solidification process of Ti6Al4V alloy wire arc additive manufacturing. Moreover, the influences of temperature field on solid-liquid transition as well as the initial I-Ti nucleation and growth in different manufacturing stages were analyzed by three-dimensional mode in different stages (deposition layer), grain nucleation and growth model and three-dimensional heat transferring (including latent heat release) model. The results show that β-Ti crystal has extremely disordered orientation and fine grain size in initial solidification stage (the first layer). Besides, with the increase of manufacturing sample height and the decrease of temperature gradient, both the average mushy zone width and average primary β-Ti grain size increase, and the crystal orientation tends to heat transfer direction (vertical cold-board direction). Final, the results of initial β-Ti crystal growth simulation basically conform to the actual additive manufacturing.
Key words: CAFE; alloy wire; arc; additive manufacturing; Ti6Al4V; crystal growth
