Properties of 310S stainless steel coatings produced by unbalanced magnetron sputter deposition

310S stainless steel coatings were produced using unbalanced magnetron sputter deposition technique. Different deposition parameters (Ar working pressure and bias voltage) were used during coating operations. It was found that the 310S coatings have a ferritic (bcc) phase structure; and the lattice parameter varies with the bias voltage and Ar pressure. Ar pressure has an important effect on the coating hardness. As Ar pressure increases from 2.67 to 8.0 × 10−3 mbar (1 mbar = 0.75 Torr), there is an abrupt drop in coating surface hardness. This was explained with the formation of different coating microstructures according to the Thornton's model. With increasing Ar pressure, surface roughness increases, indicating that the coating surface becomes more complex.