3D打印TC4钛合金粉末制备方法及组织性能研究

Study on Preparation and Microstructure and Properties of 3D Printing TC4 Titanium Alloy Powder

3D打印技术是一种快速成型技术,钛及钛合金由于具有优异的物理、化学和力学性能,广泛应用于多个领域,钛及钛合金粉末是3D打印重要的原料。介绍了制备钛及钛合金粉末的几种主要方法,重点阐述了等离子旋转电极雾化法制备钛合金粉末的原理,并对其微观组织演变规律和热处理方法进行了研究。研究结果表明,此方法制备的TC4钛合金粉末,易获得近球形的颗粒粉末,表面光洁,流动性好,具有良好的粉末特征;钛合金的显微组织由粗大柱状晶组成,柱状晶沿着堆积层的方向生长,由于温度梯度的影响,远离基材区域的晶粒尺寸大于靠近基材区域的晶粒尺寸,原始柱状晶的内部微观组织由细针状α相马氏体组成。采用固溶+时效热处理,加以空冷的冷却方式,使得在970℃/AC/1h+540℃/AC/4h条件下形成的网篮组织,强度和塑性都较好,其性能满足TC4合金3D打印要求。

3D printing is a rapid prototyping technology. Titanium and titanium alloys are widely used in manyfields because of their excellent physical,chemical and mechanical properties. Titanium and titanium alloy powderis an important raw material for 3D printing. Several main methods for the preparation of titanium and titanium al-loy powder are introduced. The principle of the preparation of titanium alloy powder by the atomization of plasmarotating electrode is emphasized,and the microstructure evolution and heat treatment methods are also studied.The results show that the TC4 titanium alloy powder prepared by this method is easy to obtain near spherical parti-cle powder. The surface is smooth,good fluidity and good powder characteristics. The microstructure of the titani-um alloy is composed of coarse columnar crystals. The columnar crystal grows along the direction of the stackinglayer. It is far away from the base material area due to the influence of temperature gradient. The grain size of theoriginal columnar crystal is composed of fine needle-like martensite. Using solid solution ＋ aging heat treatmentand cooling the air cooling method,the strength and plasticity of the net basket formed at 970 /AC/1h＋540 C /AC/4h are good,and the performance meets the 3D printing requirement of TC4 alloy.