School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran; Center for Nano-Wear, Yonsei University, Seoul 03722, South Korea.
School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran, Iran.
Ultrason Sonochem. 2017 Nov;39:698-706. doi: 10.1016/j.ultsonch.2017.03.061. Epub 2017 May 22.
The surface of β-type Ti-Nb-Ta-Zr (TNTZ) alloy, which is a promising material for biomedical applications, was treated with the ultrasonic nanocrystal surface modification (UNSM) technique to enhance its hardness. As a result, a gradient nanostructured (GNS) layer was generated in the surface; the microstructure of the top surface layer consisted of nanoscale lamellae with a width of about 60-200nm. In addition, there were lamellar grains consisting of nanostructured subgrains having unclear and wavy boundaries. The treated surface exhibited a hardness value of ∼385HV compared to 190HV for the untreated alloy. It was further determined that highly dense deformation twins were generated at a depth of ∼40-150µm below the UNSM-treated surface. These deformation twins led to a significant work hardening effect which aided in enhancing the mechanical properties. It was also found that UNSM treatment resulted in the formation of micropatterns on the surface, which would be beneficial for high bioactivity and bone regeneration performance of TNTZ implants.
β 型 Ti-Nb-Ta-Zr（TNTZ）合金是一种有前途的生物医学应用材料，其表面采用超声纳米晶表面改性（UNSM）技术进行处理，以提高其硬度。结果，在表面产生了梯度纳米结构（GNS）层；顶层表面的微观结构由宽度约为 60-200nm 的纳米级薄片组成。此外，还有由具有不清晰和波浪状边界的纳米结构子晶粒组成的层状晶粒。处理后的表面硬度值约为 385HV，而未经处理的合金硬度值为 190HV。进一步确定，在经过 UNSM 处理的表面以下约 40-150µm 的深度处产生了高密度的变形孪晶。这些变形孪晶导致了显著的加工硬化效应，有助于提高机械性能。还发现，UNSM 处理在表面形成了微图案，这有利于提高 TNTZ 植入物的高生物活性和骨再生性能。
