Study On Static Chemical Liquid Assisted Laser Processing Of Custom 455 Stainless Steel

Laser processing is widely used in medical,aerospace and other fields due to its high precision and high efficiency processing.Chemical processing does not generate thermal stress and the processing quality is good.Therefore,the combination of the two methods fully exerts the thermo-mechanical effect of the laser.The cooling and corrosive action of the chemical liquid makes the chemical liquid assisted laser processing method have a very broad application prospect.However,due to the large number of process parameters involved in chemical liquid assisted laser processing,the research on composite processing methods is still in the exploration stage.Therefore,in order to play the combined role of chemical liquid assisted laser processing,it is necessary to further study the mechanism of processing technology.Firstly,this paper analyzes the research status of laser processing technology.On this basis,the mechanism of interaction between static solution assisted laser processing is analyzed,and the main factors affecting solution assisted laser processing are discussed.The ABAQUS was used to simulate the temperature field distribution of the laser line scanning stainless steel surface in liquid environment,and the distribution of temperature field at different time points was analyzed.Secondly,the simulation results were used as a reference,and the experiment of assisting laser groove etching with solution was carried out.In order to study the influence of chemical concentration and laser parameters on the etching groove of stainless steel surface,the method of line scanning filling is used for processing.The experimental scheme adopts the static chemical liquid-assisted laser processing method with less research.The liquid medium is H₂SO₄ solution.The factors affecting the processing quality are studied by single factor experiment method,and the characterization parameters after processing?depth,width and surface roughness?were analyzed.The results show that during the laser single-line ablation process,the concentration of H₂SO₄ solution is larger,the smaller the processing area is,the better the edge straightness is,but the change is not much after 10%,and the solution concentration has little influence on the depth of material removal.It is found that the increase of the solution concentration will increase the straightness of the linear processing edge;during the process of filling and scanning the groove,it is found that the laser energy of the fixed point can be increased by increasing the power or decreasing the scanning speed within a certain parameter range.The groove depth,but at the same time,affects the roughness of the bottom of the groove,which makes the bottom topography worse.At the same time,the scanning interval,the number of scans and the progressive angle which affect the line overlap rate will affect the etching depth,and the depth is deeper.The bottom roughness of the groove is worse.Therefore,the groove etching process on the stainless steel surface can be realized by a fast,multiple processing method.Finally,the liquid medium is changed to a H₂SO₄ solution with a concentration of 10%,and the orthogonal experimental study of the surface of the stainless steel assisted by sulfuric acid solution was carried out.Based on the study of the etching effect in sodium nitrate solution,the orthogonal experimental design was carried out for the factors that have little influence on the etching depth and have great influence on the roughness.The morphology and surface roughness before and after the experiment were used as the evaluation indicators.The results show that the stainless steel surface assisted by acid solution can effectively reduce the surface roughness,and the scanning speed has the greatest influence on the surface roughness.The reason for the analysis is that the scanning speed is too slow during the filling scanning process,which leads to excessive laser energy density at the fixed point,and the ablation effect is obvious;On the other hand,because the speed is too slow,the fixed-point laser irradiation time is too long,and the sulfuric acid will corrode the stainless steel.