Influence of High-Temperature Compression on Microstructure and Properties of Sintered Molybdenum

Abstract

The high-temperature compression of sintered molybdenum was performed at 1200 °C and strain rate of 0.1 s⁻¹ on Gleeble 3500 system, and the deformation amount reached to 50%. The density, Vickers hardness, microstructure, and texture of sintered and compressed molybdenum specimens have been measured and evaluated by Archimedes method, Vickers hardness tester, optical microscopy (OM), and X-ray diffraction (XRD), respectively. The results show that the relative density of Mo specimen increases from 95.9 to 99.4% after high-temperature compression, which is close to fully dense. The Vickers hardness HV10/10 significantly is raised from 174.5 ± 6.8 MPa to 224.1 ± 21.0 MPa. The percentage of hardness fluctuation increases from 7.8 to 18.7%, which indicates that the uniformity of hardness distribution is decreased, and the hardness distribution shows a certain regularity. Combined with optical microstructure, it can be found that there are hard-deforming zone (zone I), free-deforming zone (zone III), and easy-deforming zone (zone II) in the compressed specimen. The texture analysis shows that there is a certain intensity of 〈113〉//ND fiber texture in the sintered Mo specimen, while there are multiplex textures in the compressed one, including the {112}〈111〉, {001}〈100〉, {001}〈110〉, and the residual {113}〈111〉 sintering texture.