MILLING FORCE AND SURFACE TOPOGRAPHY OF Ti-6Al-4V TITANIUM ALLOY CLADDED BY THE LASER

After the damaged blade is repaired by laser cladding, the quality of the recontouring by milling determines its working performance in reservice. Ti-6Al-4V, titanium alloy, commonly used as the material of manufacturing aero-engine blades, is selected as the experiment material. Laser cladding technology is used to prepare a cladding layer, and milling experiments are carried out on the cladding layer. The effects of milling process parameters on the milling force, roughness, and surface topography are studied. The results show that when the milling speed (v) increases to 50m/min, the milling force and roughness (Ra) reach the maximum and at this moment the surface topography is the worst. Afterwards, with an increase in v, both the milling force and Ra decrease in proportion, and the surface topography also becomes better. As the feed per tooth (fz) increases, the milling force and Ra also increase. However, the increasing trend gradually slows down. After fz increases to 0.08mm/z, the milling force and Ra almost no longer increase and the surface topography remains almost unchanged. With an increase in milling width (ae), the milling force and Ra increase on the whole. But while ae increases from 0.4mm to 0.8mm, the milling force and Ra increase very slowly. When ae reaches over 0.8mm, the milling force and Ra increase rapidly again. As ae changes, the surface topography changes according to the milling force and roughness. On this basis, it is found that while machining a laser cladding layer, the milling force directly affects the surface roughness and topography. Therefore, by adjusting v, fz, and ae, one can obtain the small milling force and good milling surface of the laser cladding TC4 layer.