The research of the effect of laser sintering modes on the thickness of the sintered cobalt-chromium-molybdenum powder layer

In the modern economic paradigm to reduce the term of the new product launch the technology of layer-by-layer laser sintering is used. Technological development is moving towards the introduction of new powder materials and definition of rational technological modes of formation of the surface layer of a given quality. The creation of applicative product is possible only within a certain range of laser exposure, which is chosen experimentally for particulate material. The accuracy of the product is greatly influenced by the layer thickness. The results of experimental studies of the effect of technological modes of powder materials sintering (the laser power, the velocity of the laser beam scanning step, pre-heating temperature of the powder material) on the thickness of the sintered cobalt-chromium-molybdenum powder layer. The studies are conducted using the technological laser complex for formation of the surfaces of the parts with a complex spatial form. The thickness of the sintered layer is determined by a specially developed technique using a digital engineer microscope. The mathematical dependence of the thickness of the sintered surface layer on cobalt-chromium-molybdenum powder sintering conditions based on the theory of experimental design and statistical treatment of results is obtained. Graphs with superposition of experimental values of the sintered layer thickness depending on the sintering conditions are plotted using mathematical relationship. Characteristic curves analysis identifies the relevant modes parameters: lasing power, laser beam traversing speed, laser beam scanning step. All these parameters affect the thickness of the sintered layer and also limits its change from 0,65 to 1 mm by increasing the laser power from 10 to 20 watts; from 0,65 to 0,88 mm by reducing the moving speed of the laser beam from 300 to 100 mm/min; from 0,9 to 1,27 mm by reducing the laser beam scanning step from 0,15 to 0,1 mm; from 0,88 to 0,91 mm by increasing the heating temperature of the powder material from 26 to 200 degrees C.