Abstract
The application of a specially developed metal composite material using LDPE polymer as a binder in additive technology is described. Nitrogen environments can facilitate the formation of chromium nitride (Cr2N), particularly at temperatures between 500-600°C, adversely affecting the material's corrosion resistance. Following binder removal, the sintering process involves heating the loosely packed particles to a temperature between 70-90% of the metal powder's melting point, facilitating the powder's dense fusion and consolidation. In the metallographic study, the austenitic grain structure was shown, and the average size was 7±3 μm. Using this raw material in additive technology, a sample was developed and annealing and ripening processes were carried out in a hydrogen atmosphere up to 1387°C based on the removal of the binder in the developed sample. Complete degradation of the polymer was achieved at 500°C, with residual mass percentage (R) analysis from TGA curves revealing 94.5% steel powder, which corresponds to the expected 94.2% mass composition. Phase analysis showed the presence of an austenitic phase, which confirmed that treatment in a hydrogen-reducing atmosphere effectively protected the samples from oxidation and additional impurities. The uncontrolled cooling rate was quite slow (1-2°C/min), which allowed the powder to continue growing until it reached the recrystallization point. As a result of the microstructure analysis of the prepared sample, a level of 250 MPa and a nano-indentation hardness of 4.87 GPa were achieved. Density after sintering is 91-93%.