不同加工工艺对纯钛支架力学性能的影响

目的 探讨不同加工工艺对纯钛支架力学性能的影响。方法 分别用数控铣削、3D打印和传统铸造工艺制作纯钛试件后用X线探伤仪进行检测。试件进行一般打磨抛光和精细打磨抛光后分别测量试件表面粗糙度;用扫描电子显微镜(SEM)分别对各组试件进行表面观察;用万能试验机测量每组试件抗弯曲强度和剪切强度。结果 X线探伤仪显示部分铸造制作的试件内部含有气孔。一般打磨抛光后数控铣削表面粗糙度最小,3D打印粗糙度最大;精细打磨抛光后数控铣削表面粗糙度变化最小;扫描电镜显示数控铣削制作的试件表面致密纹路清晰。万能试验机测量强度显示:数控铣削制作的试件其抗弯曲强度与剪切强度均为最大。结论 数控铣削加工后的纯钛试件结构最为致密,表面粗糙度最小,力学强度最大。

Effect of different processing techniques on mechanical properties of pure titanium stents

Objectives The effects of different processing techniques on the mechanical properties of pure titanium stents were observed. Methods Pure titanium specimens were made by CNC cutting, 3D printing and traditional embedding casting and tested by X-ray flaw detector. The surface roughness of specimens were measured by general grinding and fine polishing after polishing. Scanning electron microscopy (SEM) was used to observe the surface of each group of pure titanium specimens. The universal force measuring machine was used to measure the mechanical strength of each group of specimens. Results The X-ray flaw detector shows that the test piece produced by partial casting is filled with air holes; the surface roughness measured after grinding and polishing generally shows the minimum surface roughness of the CNC cutting surface and the maximum roughness of 3D printing. The change in the surface roughness of the CNC cutting after fine grinding and polishing is minimal.The SEM shows that the surface of the test piece made by CNC cutting is generally clear after grinding, and the surface of the other two parts is rough, the surface is smooth after fine grinding. The mechanical strength measured by the universal dynamometer displays that the bending strength and shear strength of the specimens produced by CNC cutting are the largest. Conclusion After CNC machining, the specimens have the most compact structure, the smallest surface roughness and the highest mechanical strength.