Influence of Temperature on Mechanical Properties and Spall Damage of Invar36 Alloy

This study systematically investigated the effects of temperature on the spall behavior of Invar36 alloy through plate impact experiments and microstructural characterization techniques. Utilizing a single-stage light gas gun loading platform combined with a high-temperature heating device, the experiments measured free surface velocity profiles and spall strength variations in samples with different segregation orientations within the temperature range of 20°C to 300°C. Results demonstrate that the spall strength of Invar36 alloy exhibits a linear decrease with increasing temperature, with elevated temperatures significantly weakening its dynamic tensile resistance. Microstructural damage analysis reveals that at room temperature, voids nucleate and propagate along element segregation bands, while high-temperature damage concentrates at grain boundaries. Elevated temperatures reduce the constraining effect of segregation and facilitate material softening through thermally activated dislocation motion. The research elucidates the central role of temperature in governing spall strength and damage mechanisms, providing a theoretical foundation for failure-resistant design of Invar alloys under high-temperature impact conditions.