选区激光熔化TC4粉末制备及成形工艺研究

为了提高气雾化制粉方法制备钛合金粉末的性能,使其更适应增材制造工艺,采用自主研发设计的电极感应气雾化制粉设备(EIGA)制备TC4钛合金粉末,研究雾化器气流汇聚角度对粉末粒度、粉末形貌的影响,采用马尔文激光粒度分析仪、氧氮氢分析仪、霍尔流速计、松装密度检测仪和工业CT等设备对粉末氧氮含量、流动性和空心粉含量进行测试。利用Concept Laser M2选区激光熔化设备对TC4粉末进行打印工艺验证研究,对比不同打印方向拉伸试样的室温力学性能,并分析选区激光熔化工艺成形TC4构件的显微组织。测试结果表明,当雾化器汇聚角度为25°时,53μm以下粉末的收得率最高,粉末性能最好。打印验证表明,粉末与Concept Laser M2打印设备的匹配度较好,力学拉伸数据能达到设备要求。因此通过改善雾化器结构能够有效提升气雾化法制备钛合金粉末的性能,并能与增材制造工艺匹配。

Study on preparation and forming process of TC4 titanium alloy powder with selective laser melting

In order to improve the performance of titanium alloy powder prepared by gas atomization method, and make it more suitable for the additive manufacturing process, the electrode induction melting inert gas atomization (EIGA) furnace which is developed and designed independently is used to prepare TC4 titanium alloy powder. The influence of convergence angle of atomizer on particles size and morphology of powder are mainly studied. Laser particle size analyzer, oxygen-nitrogen and hydrogen analyzer, hall flow meter, apparent density tester and industrial computed tomography (CT) are used to analyze the data of oxygen and nitrogen content, fluidity and the content of hollow powder. The selective laser melting machine is Concept Laser M2, which is used to research the printing process of TC4 powder, and the sample''s mechanical properties of tensile is compared in different printing directions at room temperature. Microscopic structure of TC4 component by SLM is analyzed. It shows that when the convergence angle of atomizer is 25°, the yield of powder under 53 micron is highest, and the performance of powders is best. The performance of powder on Concept Laser M2 is good, and the test data of mechanical tensile can meet the facility request. Changing the structure of atomizer can improve the performance of titanium alloy powder effectively, and the powder can be suitable for the additive manufacturing process.