Effect of heating rate on the microwave sintered W-Ni-Fe heavy alloys

In this paper, the effect of heating rate on the microwave sintered 90W-7Ni-3Fe heavy alloys was investigated, with the heating rate in the range from 10 to 112 degrees C/min. When the alloys were sintered at the heating rate from 20 to 105 degrees C/min, they exhibit excellent properties with the relative density over 99%, tensile strength between 850 and 922 MPa and elongation around 20%. It has been shown that a faster heating rate results in smaller W grain size and larger W-W contiguity. The heating rate of 80 degrees C/min has the best combination of the microstructure and mechanical performance. Sintering under an optimized condition leads to the enhanced mechanical properties of 1020 MPa in tensile strength and 21% in elongation. (C) 2009 Elsevier B.V. All rights reserved.