Fabrication of nano-crystalline W-Ni-Fe alloy with Mo and rare earth element additives

Three kinds of nano-crystalline high density alloys(86W-7Ni-3Fe-4Mo, 90W-4Ni-2Fe-4Mo and 90W4Ni-2Fe-3.8Mo-0.2RE) were fabricated by a technique combining lower temperature vacuum sintering with highenergy ball milling mechanical alloying. The crystalline size and microstructures of the specimens sintered at different sintering temperatures were examined by X-ray diffraction(XRD) and scanning electron microscope(SEM). The results show that the optimal sintering temperature of 86W-7Ni-3Fe-4Mo, 90W-4Ni-2Fe-4Mo and 90W-4Ni-2Fe3.8Mo-0.2RE alloys are 1 300 - 1 350 ℃. When they are sintered at 1 300 ℃ for 75 min, the hardness of three kinds of specimens can reach above HRC30, the relative density can reach above 96%,and 90W-4Ni-2Fe-3.8Mo-0.2RE alloy possesses the best integrated properties, its hardness is HRC35 and its relative density is 98%.