Wear behavior of aluminum-matrix particle (TiH2 and ZrH2)-reinforced composite foam additively manufactured using directed energy deposition

In this study, we comparatively analyzed the wear characteristics of particle-reinforced composite foams (PRCF) manufactured by blending foaming agents (TiH2 and ZrH2) with AlSi10Mg powders based on the directed energy deposition technology. Wear test results showed that the deposited AlSi10Mg fabricated with ZrH2 had the best wear resistance. In the PRCF (ZrH2), friction fluctuations were highest due to the presence of many pores on the specimen surface. However, these pores were filled with wear debris produced due to the abrasion, which flattened the surface and reduced the friction coefficient. Owing to the intermetallic compound formed upon the reaction between AlSi10Mg and foaming agent, only a part of the aluminum matrix was removed due to wearing. Thus, the weight loss was lower compared to those of the deposited AlSi10Mg. Grain refinement due to the foaming agent and strain hardening due to the intermetallic compound were superior to those of deposited AlSi10Mg. There were significant differences in the formation of the pore and intermetallic compound according to the type of foaming agent, which resulted in a difference in the wear mechanism.