Research On Laser-EDM Manufacturing Technology Of Titanium Alloy Functional Surfaces

In this paper,titanium-alloy surface laser-electric spark composite manufacturing technology is used to realize titanium alloy friction-reducing and wear-resistant functional surface manufacturing.By studying two methods of laser-assisted electric discharge wire-cutting and laser-electric spark asynchronous machining,the influence of parameters such as pulse width,laser power and microstructure spacing on the surface quality and surface function of titanium alloy was studied.First of all,laser-assisted electric discharge wire cutting machining experiments were carried out,the research route was designed,and experimental studies were carried out.The results show that the surface hardness of titanium alloy can be increased compared with traditional WEDM,but it is easy to produce cracks,and the surface residual tensile stress is large.Laser-assisted wire-cut electric discharge machining has reduced surface cracks and shallower depths,the surface hardness has not changed significantly,but the thickness of the hardened layer has increased significantly,the surface residual stress value decreases,the surface roughness value decreases,and the surface friction coefficient increases with the pulse width.Friction coefficient is lower than the surface of conventional processing samples,the lowest value of 0.16.The wear resistance of the surface is better than that of the substrate,and the amount of mass wear per unit time is nearly one order of magnitude lower than that of the substrate.Secondly,a laser-electric spark asynchronous composite machining test was carried out.The steps are: firstly cutting the surface of the titanium alloy by electric spark wire cutting,and then processing the lattice structure on the surface with a laser to obtain a functional surface.The influence of the laser power and the center distance of the lattice on the surface quality and surface function of the titanium alloy was studied.The experimental results show that the surface roughness of titanium alloy increases with the increase of laser power and decreases with the increase of the lattice center distance.The surface hardness decreases with the increase of laser power and increases with the decrease of lattice center distance.Under certain parameters,the surface has obtained excellent friction-reducing function and hydrophobic function,the lowest coefficient of friction is 0.17,which is lower than the matrix by more than 40%;the highest contact angle is 152°,and superhydrophobic function is realized.