Fabrication of ZrB_2-Zr cermet using laser sintering technique

摘要

A combination of laser sintering/melting and induction heating techniques is used to fabricate ZrB_2-Zr ceramic-metal composite (cermet) 3-D structures using layer by layer deposition. It is shown that the interface between layers comprises an ～20 pm thick Zr-rich phase near the remelted zone. The starting powder mixtures consist of 30-50 wt.% Zr, which is used to assist binding of ZrB_2 particles. Sintered objects have densities ＞95% of theoretical values and have microhardness values up to 16.0 GPa. ZrB_2-Zr cermet may reduce the likelihood of mechanical failures by increasing toughness and impact resistance contributed from the continuous Zr matrix, yet preserve good abrasive characteristics provided by ZrB_2 grains. The proposed method allows fabricating complex-shaped structures, and joining or repairing objects made from analogous ultra-high temperature materials.