Microstructure and compression properties of fine Al2O3 particles dispersion strengthened molybdenum alloy
(1. Henan Key Laboratory of High Temperature Structural and Functional Materials, Henan University of Science and Technology, Luoyang 471003, China;
2. National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials, Henan University of Science and Technology, Luoyang 471003, China;
3. China National R&D Center for Tungsten Technology, Xiamen Tungsten Corporation, Ltd., Xiamen 361000, China)
2. National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials, Henan University of Science and Technology, Luoyang 471003, China;
3. China National R&D Center for Tungsten Technology, Xiamen Tungsten Corporation, Ltd., Xiamen 361000, China)
Abstract: The Mo alloys reinforced by Al2O3 particles were fabricated by hydrothermal synthesis and powder metallurgy. The microstructures of Mo-Al2O3 alloys were studied by using XRD, SEM and TEM. The results show that Al2O3 particles, existing as a stable hexagonal phase (α-Al2O3), are uniformly dispersed in Mo matrix. The ultrafine α-Al2O3 particles remarkably refine grain size and increase dislocation density of Mo alloys. Moreover, a good interfacial bonding zone between α-Al2O3 and Mo grain is obtained. The crystallographic orientations of the interface of the Al2O3 particles and Mo matrix are and . Due to the effect of secondary- phase and dislocation strengthening, the yield strength of Mo-2.0vol.%Al2O3 alloy annealed at 1200 °C is approximately 56.0% higher than that of pure Mo. The results confirm that the addition of Al2O3 particles is a promising method to improve the mechanical properties of Mo alloys.
Key words: Mo-Al2O3 alloys; hydrothermal synthesis; interface; compression test; dispersion strengthening