He Zheyu, He Hao, Lou Jia, Li Yimin, Li Dongyang, Chen Yongzhi, Liu Shaojun
State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China.
Research Center for Materials Science and Engineering, Guangxi University of Science and Technology, Liuzhou 545006, China.
Materials (Basel). 2020 Jan 19;13(2):478. doi: 10.3390/ma13020478.
Ti6Al4V alloy has been considered as a key component used in ultrasonic scalpels. In this series of papers, the fabrication, structure, and mechanical and ultrasonic properties of medical Ti6Al4V alloys suitable for ultrasonic scalpel are studied systemically. These alloys with low elastic modulus and present a typical bimodal microstructure with relatively high β phase content (~40%) and lamellar α thickness of ≤ 0.9 µm. In the first paper, the relationship between the microstructure and mechanical properties of hot-rolled Ti6Al4V alloys treated by heating treatment is discussed. In the second paper, the dependence of the ultrasonic properties on the microstructure of the heat-treated Ti6Al4V alloys is reported. With increasing solid solution temperature, the content and size of the primary α phase decrease. In contrast, the content and size of the lamellar α phase increase. Additionally, the β phase content first increases and then decreases. The microstructure of Ti6Al4V alloys could be slightly changed by aging treatment. When the solid solution treatment temperature increases to 980 °C from 960 °C, the average size of the lamellar α phase in the alloys increases by 1.1 µm. This results in a decrease in the average yield strength (93 MPa). The elastic modulus of alloys is mainly controlled by the β phase content. The microstructure of alloys by solution-treatment at 960 °C shows the highest β phase content and lowest average elastic modulus of 99.69 GPa, resulting in the minimum resonant frequency (55.06 kHz) and the highest average amplitude (21.48 µm) of the alloys at the length of 41.25 mm.
Ti6Al4V合金被认为是超声手术刀的关键部件。在这一系列论文中，系统研究了适用于超声手术刀的医用Ti6Al4V合金的制备、结构以及力学和超声性能。这些合金具有低弹性模量，呈现出典型的双峰微观结构，β相含量相对较高（约40%），片状α相厚度≤0.9μm。在第一篇论文中，讨论了热处理后的热轧Ti6Al4V合金微观结构与力学性能之间的关系。在第二篇论文中，报道了超声性能对热处理Ti6Al4V合金微观结构的依赖性。随着固溶温度的升高，初生α相的含量和尺寸减小。相反，片状α相的含量和尺寸增加。此外，β相含量先增加后减少。时效处理可使Ti6Al4V合金的微观结构略有变化。当固溶处理温度从960℃升高到980℃时，合金中片状α相的平均尺寸增加1.1μm。这导致平均屈服强度降低（93MPa）。合金的弹性模量主要由β相含量控制。在960℃进行固溶处理的合金微观结构显示出最高的β相含量和最低的平均弹性模量99.69GPa，在长度为41.25mm时，合金的共振频率最低（55.06kHz），平均振幅最高（21.48μm）。
