A method for producing an irregular tungsten/matrix interface in tungsten based heavy alloy is disclosed. The method involves a cyclic heat treatment and resintering at above liquidus temperature for tungsten heavy alloys consisting of 80 to 98 weight % tungsten and remainder of matrix phase. The sintered specimens are cyclically heat treated at above 1000.degree. C. and resintered at liquidus temperature of the matrix phase for one minute to 4 hours at a constant temperature.
Tungsten-based alloy material sintered at a high sintering power that may contain additive elements soluble in the nickel and selected from the group constituted, for example, by rhenium, molybdenum, tantalum, niobium, vanadium or a mixture of these, wherein, after sintering in liquid phase at a temperature of around 1500.degree. C., it has: a two-phased .alpha.-.gamma. microstructure that is fully densified, has no porosities or has negligible porosities of a low mean grain size (L.alpha.) and a contiguity (C.alpha..alpha.) that is very low with respect to the size of the tungsten crystals, and a dispersion of micro-oxides with no loss of ductility properties.
