Transition metal diborides are ceramic materials with potential applications as hard protective thin films and electrical contact materials. We investigate the possibility to obtain age hardening through isostructural clustering, including spinodal decomposition, or ordering-induced precipitation in ternary diboride alloys. By means of first-principles mixing thermodynamics calculations, 45 ter...

Two compositions of ZrB2-based ceramic composites containing Si3N4, Al2O3 and Y2O3 have been hot-pressed at different temperatures between 1673 and 1773 K for 60 min in vacuum. The densification behavior of the composites was examined during the sintering process. The microstructures of the composites were characterized by scanning electron microscopy, and the crystalline phases were identified...

The high-velocity impact resistance of hot-pressed zirconum diboride with 30 volume percent silicon carbide was studied using a combined experimental and computational approach. Test specimens in the form of 2 mm thick polished disks were impacted with -0.8 mm diameter tungsten carbide spheres at velocities up to 320 d s . The intrinsic flexure strength of the specimens was -1000 MPa. The flexu...

Advisor: Bai Cui Molybdenum aluminum boride (MoAlB) is a ternary transition metal boride which has promising aeronautic and nuclear applications. It inheres excellent properties of the binary transitional metal borides (e.g., MoB, ZrB2) such as high melting temperature, high hardness, and thermal conductivity. Besides, MoAlB is superior to MoB because: (1) the Al element provides an oxidation r...

In the frame of Horizon 2020 European C3HARME research project, manufacture ZrB2-based CMCs was developed through different processes: slurry infiltration and sintering, radio frequency chemical vapour (RF-CVI) reactive metal (RMI). To assess high temperature stability, room bending strength measured after oxidizing samples at 2278 K compared to as-produced materials. Microstructures were analy...

NiAl composite coating strengthened by ZrC and ZrB2 phases is synthesized the plasma cladding process. The influence of speed on microstructrue properties coatings studied. main are NiAl, γ-(Fe,Ni), phases. in shape points small blocks, shows long strips needle bar. slower speed, larger size reinforcing With increase wear resistance improves. Coating with 10mm/s has excellent wear-resistance pr...