The invention relates to a nonmagnetic hard
alloy material and a preparation method thereof. The
alloy comprises (wt %)
tungsten carbide 75-90,
nickel powder 8-20,
chromium carbide 0.5-3.0, and
vanadium carbide 0.3-2.5. The preparation method comprises compounding,
wet grinding,
drying, pressing,
sintering and checking, wherein in the
wet grinding step, a nonmagnetic
alloy lining board wet grinder is used,
alcohol or
acetone is added as
grinding medium, nonmagnetic hard alloy balls is used as
grinding material, the ratio of
grinding medium to material is 5:1, the
solid-to-
liquid ratio is 350ml / Kg, and the
wet grinding time is 48-56 hours; and pressure
sintering is adopted. In the inventive nonmagnetic hard alloy material, fine-particle
tungsten carbide
powder (1.0-1.5 mum) is used as hard phase, so as to improve the
hardness and abrasion resistance of the alloy. The
nickel is used as binder, and a small amount of
chromium carbide and
vanadium carbide are added as
tungsten carbide
grain growth inhibitor, so as to refine
tungsten carbide crystal grains, and further improve the
hardness and abrasion resistance of the alloy. The pressure
sintering technique accelerates densification speed during sintering process, effectively reduces
porosity of the alloy, and remarkably improves the strength of the alloy.