Abstract:An advanced Co-25W alloy used for producing aviation apparatus axle journals and its technological processes were described. Because high-purity raw materials and consumable-electrode refine technology were used, the content of oxygen and other impurities in the alloy were reduced to 0.011 % and 0.5~1.0 grade respectively. So, the hot-working properties of the alloy was considerably improved. When deformation temperature and cross-section shrinkage ratio of each procedure including forging, hot-rolling, rotary forging and wire-drawing were well controlled, the alloy could be drawn into wire of 0.50mm in diameter. Its Vickers hardness (Hv) of as-drawn alloy was 4500~5500MPa, and it could be improved to more than 7200MPa to meet the requirements of axle journals, which was ascribed to age pricipitated Co3W phase in vacuum orH2atmosphere. The optimum aging temperature was 650℃, aging time 8 h. By means of metallography and XRD, microstructure changes in the course of processing, many factors influencing the process properties of the alloy and their choice principles were discussed in details. The influences of aging temperature and time on hardness of Co-W alloy and the age-hardening mechanism were investigated.

Key words: Co-25W alloy　axle journals　consumable-electrode melting　wire-drawing　age-hardening