Essay On Powder Metallurgy

Some of the advantages of powder metallurgy (PM) alloys include low cost, complex shapes, alloy flexibility, wide range of reinforcement levels, and ability to use metastable structures [1, 2]. Furthermore, with powder metallurgy technique it is possible to obtain a homogeneous distribution of the reinforcement in the matrix without excessive matrix–reinforcement reaction, which is often a problem in techniques like squeeze infiltration or stir casting of the reinforcement in the molten matrix under a dry and protective atmosphere. This is due to the formation of transient liquid phase during sintering. The liquid phase penetrates between the matrix grain boundaries at the case of satisfactory wetting of the matrix by the melt.

Metal matrix

The wear analysis of Fe–Al alloys with Fe being the base matrix is deficient in the literature [19, 20]. Perhaps one of the inimitable studies on the worn surfaces for Fe–Al alloys was reported by Xu et al [21], where the Fe–Al alloys were found to exhibit high wear resistance. They found that as the load increased, the friction coefficient decreased slightly due to the rise of the friction contact temperature and the larger areas of the oxidized film on the worn surface which act as a solid lubricant. Increasing the load leads to increasing the shear stress at the deeper position below the surface. Thereby aggravating the wear [21] as aluminum affects the flexibility of the alloy. Kim et al [22] found that the wear rate of the iron-aluminides containing 25, 28 and 30 at.% aluminum increased with the increase of the applied normal load and the wear sliding speed. Wear resistance of the aluminides decreased with the increase in aluminum contents and the SEM observations of worn surfaces of the iron-aluminides showed ductile material’s wear behavior associated with plastic deformation