German Randall M
Mechanical Engineering, San Diego State University, 5500 Campanile Drive, San Diego, CA 92128, USA.
Materials (Basel). 2013 Aug 20;6(8):3641-3662. doi: 10.3390/ma6083641.
Metal powder injection molding is a shaping technology that has achieved solid scientific underpinnings. It is from this science base that recent progress has occurred in titanium powder injection molding. Much of the progress awaited development of the required particles with specific characteristics of particle size, particle shape, and purity. The production of titanium components by injection molding is stabilized by a good understanding of how each process variable impacts density and impurity level. As summarized here, recent research has isolated the four critical success factors in titanium metal powder injection molding (Ti-MIM) that must be simultaneously satisfied-density, purity, alloying, and microstructure. The critical role of density and impurities, and the inability to remove impurities with sintering, compels attention to starting Ti-MIM with high quality alloy powders. This article addresses the four critical success factors to rationalize Ti-MIM processing conditions to the requirements for demanding applications in aerospace and medical fields. Based on extensive research, a baseline process is identified and reported here with attention to linking mechanical properties to the four critical success factors.
金属粉末注射成型是一种有着坚实科学基础的成型技术。正是基于这一科学基础,钛粉末注射成型才有了近期的进展。大部分进展都等待着具有特定粒度、颗粒形状和纯度等特性的所需颗粒的研发。通过深入了解每个工艺变量如何影响密度和杂质水平,注射成型钛部件的生产得以稳定。如下所述,近期的研究已经确定了钛金属粉末注射成型(Ti-MIM)中必须同时满足的四个关键成功因素——密度、纯度、合金化和微观结构。密度和杂质的关键作用,以及烧结过程中无法去除杂质,使得人们必须关注使用高质量合金粉末来开始Ti-MIM工艺。本文阐述了这四个关键成功因素,以使Ti-MIM工艺条件符合航空航天和医疗领域苛刻应用的要求。基于广泛的研究,本文确定并报告了一个基线工艺,重点是将机械性能与这四个关键成功因素联系起来。