Microstructure and Properties of Rolled Tungsten Alloy at Different Annealing Temperatures

Rolled tungsten alloy has the characteristics of high hardness and high strength, which brings a lot of inconvenience to later processing. Therefore, in order to better avoid the waste of raw materials in later production, we need to study and understand the influence factors that change the structure and properties of rolled tungsten alloys. The following is an experimental analysis of the effect of annealing temperature on the mechanical properties and microstructure of the rolled 95WNiFe alloy.

Experimental method

The reduced tungsten powder, electrolytic nickel powder and carbonyl iron powder are mixed and mixed with a binder, and then molded by compression molding. After dewaxing, the green compact is liquid-phase sintered to obtain a calcined compact size of 130mm×105mm×3.86mm. The relative density reaches more than 99%. The sintered billet is rolled in one direction using the JM250 reversible cold rolling mill. After multiple passes, the final material deformation reaches 89.9%. Observe the microstructure of the sintered and deformed materials, and compare the deformed shapes. The 95WNiFe alloy was annealed at four different temperatures of 800℃, 1000℃, 1200℃ and 1450℃, and the annealing time was 1h. The performance of the alloy samples at different annealing temperatures was tested, and the microstructure morphology was observed.

Experimental results

1) The 95WNiFe alloy whose rolling deformation reaches 89.9% is annealed at 800°C and 1000°C. The microstructure and properties of the alloy are the same as those in the rolled state. There is no recrystallization of tungsten particles, and the tensile strength of the alloy is still maintained. At 1215MPa, the elongation is 3%.

2) When the annealing temperature reaches 1200℃, the rolled alloy begins to recrystallize, the tensile strength of the alloy decreases to 1050MPa, and the elongation increases to 8%.

3) When the annealing temperature reaches 1450℃, the tungsten particles are spherical and the binder phase is distributed around the tungsten particles, which is basically the same as the sintered structure. The tensile strength and elongation of the alloy also reach the level of the sintered state, respectively 900MPa And 14%.