Zr4 H4

Zr₄H₄ is a zirconium hydride compound—a brittle intermetallic phase formed when zirconium absorbs hydrogen. This material is primarily encountered in zirconium metallurgy rather than as a deliberately engineered material; its formation represents a degradation pathway in zirconium and zirconium alloys when exposed to hydrogen-rich environments. Engineers monitor and control Zr₄H₄ precipitation because it embrittles otherwise ductile zirconium alloys, making it a critical failure mechanism in nuclear reactor cores, high-pressure hydrogen vessels, and aerospace structures where both materials must interface.