Lin Jianjun, Lv Yaohui, Liu Yuxin, Sun Zhe, Wang Kaibo, Li Zhuguo, Wu Yixiong, Xu Binshi
Shanghai Key Laboratory of Materials Laser Processing and Modification, Shanghai Jiao Tong University, Shanghai 200240, China; National Key Laboratory for Remanufacturing, Academy of Armored Forces Engineering, Beijing 100072, China.
National Key Laboratory for Remanufacturing, Academy of Armored Forces Engineering, Beijing 100072, China.
J Mech Behav Biomed Mater. 2017 May;69:19-29. doi: 10.1016/j.jmbbm.2016.12.015. Epub 2016 Dec 21.
Plasma arc additive manufacturing (PAM) is a novel additive manufacturing (AM) technology due to its big potential in improving efficiency, convenience and being cost-savings compared to other AM processes of high energy bea\m. In this research, several Ti-6Al-4V thin walls were deposited by optimized weld wire-feed continuous PAM process (CPAM), in which the heat input was gradually decreased layer by layer. The deposited thin wall consisted of various morphologies, which includes epitaxial growth of prior β grains, horizontal layer bands, martensite and basket weave microstructure, that depends on the heat input, multiple thermal cycles and gradual cooling rate in the deposition process. By gradually reducing heat input of each bead and using continuous current in the PAM process, the average yield strength (YS), ultimate tensile strength (UTS) and elongation reach about 877MPa, 968MPa and 1.5%, respectively, which exceed the standard level of forging. The mechanical property was strengthened and toughened due to weakening the aspect ratio of prior β grains and separating nano-dispersoids among α lamellar. Furthermore, this research demonstrates that the CPAM process has a potential to manufacture or remanufacture in AM components of metallic biomaterials without post-processing heat treatment.
等离子弧增材制造（PAM）是一种新型增材制造技术，因为与其他高能束增材制造工艺相比，它在提高效率、便利性和成本节约方面具有巨大潜力。在本研究中，通过优化焊丝送进连续PAM工艺（CPAM）沉积了几个Ti-6Al-4V薄壁件，其中热输入逐层逐渐降低。沉积的薄壁件具有多种微观结构形态，包括原始β晶粒的外延生长、水平层带、马氏体和篮状编织微观结构，这取决于沉积过程中的热输入、多次热循环和逐渐冷却速率。通过在PAM工艺中逐渐降低每个焊道的热输入并使用连续电流，平均屈服强度（YS）、极限抗拉强度（UTS）和伸长率分别达到约877MPa、968MPa和1.5%，超过了锻造的标准水平。由于削弱了原始β晶粒的长径比并在α片层之间分离出纳米弥散相，力学性能得到了强化和增韧。此外，本研究表明，CPAM工艺有潜力在不进行后处理热处理的情况下制造或再制造金属生物材料的增材制造部件。
