Microstructure and dynamic mechanical properties of laser alloyed coating on 97W surface

In order to improve the dynamic mechanical properties of tungsten heavy alloys, 65W10Cr5V4Co2 and 65W10Cr5V4Co2 + 2% C₃N₄ composite coatings were prepared on the surface of 97W matrix by laser alloying process. With the help of scanning electron microscope, separated Hopkinson press rod, and other experimental instruments, the microstructure, microhardness, and dynamic compression mechanical properties of the alloyed specimens were studied, and the Johnson-Cook ontological relationship of uncoated tungsten alloy and tungsten alloy with coating was fitted by using the method of separation of variables to explore the influence of composite coatings on the dynamic mechanical properties of 97W alloy. The results show that the composite coating containing 2% C₃N₄ generates complex carbides and nitrides such as (Fe, Cr)₄W₂N and (Fe, Cr)₃W₃C, and the microstructure presents a regular reticular structure with more uniform element distribution and smaller grain size; the average microhardness of the fusion-coated layer reaches 2.3 times that of the 97 W matrix; the addition of the composite coating improves the degree of strain reinforcement in the overall structural material, but the strain rate sensitivity of the overall material is reduced, and the overall structure fails in the form of W particle disintegration under the strain rate loading of 3500 s⁻¹.