Study On Process Parameters And Influencing Factors Of Selective Laser Melting Thin-walled Parts

The selective laser melting technology can form dense metal parts directly,and has become one of the hot research topics?Thin-walled parts are characterized by light weight,material saving,compact structure,etc.,and are widely used in industrial production.In order to produce fine and suitable thin-walled parts,the selective laser melting(SLM)process of thin-walled parts was studied on a self-developed SLM equipment.Firstly,the effects of different pulse width,laser power and scanning speed on the forming effect of single channel in pulsed laser mode are analyzed experimentally.It can be known from a single experiment that when the laser power is constant,the width of a single melting channel decreases with the increase of the scanning speed.The width of the single melting channel increases with the increase of the laser power.Within a certain pulse width range,the width of single melt channel increases with the increase of pulse width.After that,a rectangular block of 10 mm x 10 mm x 12 mm was formed using the optimized parameters,and the average temperature of each surface of the layer during processing was measured.The results show that the temperature increases with the increase of the forming layer,and the longer the pulse width,the faster the temperature rises.The relative density of the formed rectangular block was measured to be 86%.On the basis of single-track,the thin-walled parts with single straight-line,multi-straight-line and single-inclined pile-up are formed.The thin-walled parts with the minimum wall thickness of 70 ?m were obtained,and several thin-walled parts with the wall thickness of 0.1 mm and 0.2 mm were formed.The absolute error of the wall thickness could be controlled within 30 ?m.The theoretical wall thickness and the actual wall thickness were discussed.The surface and side of thin-walled parts were observed under optical microscope,and the powder adhesion phenomenon of thin-walled parts during forming was analyzed.For inclined thin-walled parts,the forming limit angle is 25 °.Finally,the mesh parts and arc thin-walled parts are studied.At the end of the paper,some problems of forming thin-walled parts by SLM technology are discussed,and the feasibility of using layered forming and zone scanning method is put forward.