Influence of minor elements additions on microstructure and properties of 93W�??4.9Ni�??2.1Fe alloys

[摘要] Effects of elements rhenium and chromium additions on properties and microstructure of 93Wâ€�??4.9Niâ€�??2.1Fe alloys were investigated. Optical microscope (OM), scanning electron microscope (SEM) and EDAX energy spectrometer were used to characterize the microstructure and compositions of the alloys, respectively. The tensile strength and elongation of alloys were evaluated using the quasi-static tensile testing machine, and the relative densities of the alloys were evaluated using the Archimedes water immersion method. The experimental results indicated that when elements Re and Cr were in the range of 0â€�??1.0 wt.%, relative density, elongation, tensile strength of 93Wâ€�??4.9Niâ€�??2.1Fe alloys varied from 99.4%, 26.4%, 997.2 MPa without Re additions to 99.5%, 8.6%, 1161.2 MPa with 1.0 wt.% Re addition, respectively. Rhenium generated solid-solution strengthening, grain refinement, reducing ductile tearing and increasing transcrystalline fracture, which resulted in the ductility reduction and the strength increase of the heavy alloys. With the increase of Cr content from 0â€�??1.0 wt.%, the tensile strength, relative density and elongation of 93Wâ€�?�Niâ€�?�Fe alloy reduced from 997.2 MPa, 99.3%, 15% to 844.4 MPa, 95.2%, 5.7%, respectively. Element Cr formed interphases with elements W, Ni, Fe and O and gathered along the interface of the alloys, which induced interfacial cohesion and resulted in lower mechanical properties of 93Wâ€�?�Niâ€�?�Fe alloys.

[学科分类] 材料工程

[关键词] 93Wâ€�?�Niâ€�?�Fe alloys;microstructure;mechanical properties;element chromium;element rhenium.