Impurities, particularly oxygen, are a critical issue to address in metal-injection-molding (MIM) processed Ti-Nb-Zr biomaterials. The addition of rare earth (RE) elements such as yttrium is a possible solution to the impurity problem due to their potential for scavenging oxygen. The impacts of added Y on the sinterability, microstructure and mechanical properties of the MIMed Ti-Nb-Zr, however, largely remain unclear. In this study, different sized Y particles with varying weight fractions have been added to the β Ti-Nb-Zr alloy in order to elucidate the aforementioned aspects. It has been found that, although the added Y has an obvious β grain refinement effect, its impacts on the residual porosity, ultimate tensile strength and tensile toughness can be significantly negative, particularly if using large sized Y particles. Small sized (<15 μm), moderate amount (e.g. 0.3 wt%) of Y addition, however, proved to be beneficial, in terms of scavenging oxygen and promoting fracture toughness. Characterization techniques and mechanical testing are employed to understand the above experimental findings with the assistance of sintering theory and existing literature. It is hoped that the present study can provide an important guidance for using Y as an oxygen scavenger to develop low-cost, high-performance MIMed Ti alloys.

杂质，特别是氧气，是金属注射成型（MIM）处理的Ti-Nb-Zr生物材料中解决的关键问题。由于稀土元素有清除氧气的潜力，因此添加稀土元素（如钇）可能是解决杂质问题的一种方法。然而，添加的Y对MIMed Ti-Nb-Zr的可烧结性，微观结构和机械性能的影响尚不清楚。在这项研究中，具有不同重量分数的不同尺寸的Y颗粒已被添加到βTi-Nb-Zr合金中，以阐明上述方面。已经发现，尽管添加的Y具有明显的β晶粒细化效果，但是其对残余孔隙率，极限拉伸强度和拉伸韧性的影响可以显着地负面，特别是如果使用大尺寸的Y颗粒。小型（< 然而，在清除氧气和促进断裂韧性方面，适量的Y添加量（例如15μm）被证明是有益的（例如0.3重量％）。在烧结理论和现有文献的帮助下，采用表征技术和机械测试来了解上述实验结果。希望本研究能够为使用Y作为除氧剂开发低成本，高性能MIMed Ti合金提供重要指导。