Parameter optimization for selective laser melting of TiAl6V4 alloy by CO2 laser

One of the most commonly used alloys in additive technologies is the titanium alloy TiAl6V4. In recent years, a large number of works was devoted to the study of selective laser melting of the alloy when using a fiber laser. In this work, we studied the modes of the SLM with the use of carbon dioxide laser. To study the influence of parameters of selective laser melting on the porosity of the resulting material is used for the installation of SINTERSTATION® Pro DM125 SLM System. The samples were produced in an inert atmosphere (oxygen content in the chamber was 500 ppm). Powder with a particle size of from 20 microns to 63 microns, average particle size - 44 micron, the average sphericity on the parameter Roundness ISO - 63,74 % was used. The samples cubic shape were manufactured using nine different modes of melting. Porosity was determined by studies of сross-section by optical microscope (manufactured 2 сross-sections: coinciding with the direction of growing of the sample and perpendicular to the direction of growing). All the samples have a dense structure and a satisfactory surface quality. When using laser power of 100 W and exposure time of 50 µs was obtained the sample with the highest porosity (22,6 %). The pores in this case have of irregular shape and large size. The specimen with the minimal porosity (0,5 %) was obtained at laser power of 200 W and exposure time of 150 µs. Pores in this case are spherical and smaller in size.