Study on microstructure and surface microhardness of laser-assisted machining of TB8 titanium alloy

TB8 titanium alloy is widely used in the aerospace industry because of its excellent properties. In this paper, laser-assisted orthogonal micromachining of TB8 titanium alloy was carried out. Observe the microstructure of the workpiece section after processing, and measure the microhardness of the processed surface. The advantages of laser-assisted cutting are analyzed by comparing conventional cutting with laser-assisted cutting. The influence of different machining parameters on the microstructure of TB8 titanium alloy was obtained by changing different machining parameters. Compared with conventional cutting, laser-assisted cutting can greatly reduce grain fragmentation. With the increase of cutting depth, the grain fragmentation decreases first and then increases. With the increase of laser power, the grain fragmentation decreases first and then increases. The grain breakage increased first and then decreased with the increase of cutting speed, and better grain quality could be obtained with smaller and larger cutting speeds. Compared with conventional cutting, laser-assisted cutting can improve the surface hardness of the workpiece, and the maximum improvement is 16.9% when the cutting speed is 50mm/s. The surface microhardness of laser-assisted cutting increases with the increase of cutting speed, but decreases first and then increases with the increase of cutting depth.