Comparison of activation technologies powder ECP-1 for the synthesis of products using SLS

Development of methods for the synthesis of layer prototypes and finished products allows to introduce these technologies in various spheres of activity, ranging from mild to military industry and medicine. Of particular interest is the possibility of producing metal products with complex geometric shapes. Layer by layer laser sintering technology enable the use as a building material, metal powders, and mixtures thereof. The initial physical and chemical properties of powders determine the conditions and technological conditions under which will be a synthesis of the product. Such properties include particle size distribution, particle shape, melting point, thermal conductivity and others. During sintering of metal powders there is an effect of coagulation, which is bad for the quality of the sintered product. One way to change the initial properties of the powder, as well as change in the effect of coagulation is its pre-activation. This paper presents the results of experimental research, the influence of pre-activation of the powder brand ECP-1 (GOST standards 4960-09) to change its original properties. Shows the change porosity and mechanical strength of samples produced by selective laser sintering (SLS), depending on the method of activation of the powder. Activation of powder conducted gamma radiation radioactive isotope Co 60 and mechanically. The bulk density of the powder was determined by the «funnel». Changing the structure of the powder was determined on the metallographic microscope. The experimental samples were made on the technological of laser complex «VARISKAF-100M». The mechanical compressive strength was determined on a desktop universal testing system. Experimental results have shown that the mechanical activation significantly altered granulometric properties of the powder. The powder particles agglomerate plate-sizes up to 0.5 mm. The bulk density of the powder, which is activated by mechanical means, increases up to 35 % in the processing time of 1.5 min. and 45 % at 3 min. In consequence of the laser impact such processes as sintering of the powder particles and their complete fusion are observed. When activated by ionizing radiation structure and bulk density of the powder does not change. During sintering there is increased oxidation of the material and the shrinkage of the sample.

selective laser sintering, powder ECP-1, mechanical activation, ionizing radiation