High temperature interaction between molten Ni50Al50 alloy and ZrB2 ultra-high temperature ceramics

In this work, Ni50Al50 alloy is taken into consideration as potential brazing material for joining ZrB2 ultra-high temperature ceramic. The results of experimental study on high interfacial phenomena between molten binary and polycrystalline ZrB2, are shown. A sessile drop method combined with a capillary purification procedure was applied to investigate the wetting behavior Ni50Al50/ZrB2 couple during holding 400 s at 1688 °C (i.e. T = 1.02Tm). It found that rapidly wets spreads over surface while involved reactive infiltration solid substrate allowed reaching final contact angle ~0° in 250 s. kinetics much faster than reported literature Cu, Ag or Au tested 1.05Tm. solidified subjected SEM/EDS microstructural characterization order reveal course phenomena. point towards (I) an existence Ni-enriched Ni-Al/ZrB2 layer; (II) formation zone assisted by reactively formed Al2O3 due reaction Al-rich melt (III) partial transfer phase dissolution/precipitation mechanism.