Effect of tungsten addition on the toughness and hardness of Fe2B in wear-resistant Fe–B–C cast alloy

The effects of tungsten additions of 0%, 1.12%, 2.04%, and 3.17% (in wt.%) on the morphology, fracture toughness and micro-hardness of Fe2B in Fe–B–C cast alloy were investigated. The results indicate that, with the increase of tungsten addition, the morphology and distribution of Fe2B have no change and a new W-containing phase, except the (Fe, W)2B with a certain tungsten solution, does not form, and that the fracture toughness of Fe2B increases first and then decreases, while the hardness increases first and then has a little change. Compared with the fracture toughness (3.8 MPa·m1/2) of Fe2B without tungsten addition, the toughness at 2.04 wt.% tungsten can be improved by about above 80% and achieves about 6.9 MPa·m1/2, and variation characteristics of hardness and toughness of Fe2B were also testified by viewing the indentation marks and cracks on the Fe2B, respectively.

► Poor toughness of Fe2B decreases obviously the wear resistance of the alloy.
► As W content increases, Fe2B’s toughness increases first and then decreases.
► As W content increases, Fe2B’s hardness first increases and then has little change.
► The toughness at 2.04 % W can be improved by above 80% more than that at 0% W.