Tensile mechanical properties and fracture behavior of tungsten heavy alloys at 25-1100 °C

The tensile mechanical properties and fracture behavior of three tungsten heavy alloys (fine-grained 93W-4.9Ni-2.1Fe-0.03Y; coarse-grained 93W-4.9Ni-2.1Fe; coarse-grained 95W-3.5Fe-1.5Ni, wt%) have been investigated in the temperature range from 25 to 1100. °C. The results show that ultimate tensile strength, yield strength, fracture strength and nominal total elongation of the three tungsten heavy alloys are strongly temperature-dependent and in most cases decrease with increasing temperature. Fractographic observations using scanning electron microscopy (SEM) show that the fracture modes of the three alloys evolve from a mixture of W cleavage and matrix phase ductile rupture at low temperatures to a mixture of tungsten/matrix and tungsten/tungsten interfacial debonding failure at elevated temperatures.