Sintered Ti-system material product derived from injection molding of powder material and producing method thereof

A sintered Ti-base material product derived from injection molding of a powder material, which comprises a carbon amount of not less than 0.2 mass % to not more than 1.0 mass %, wherein:

• the outer layer region of the product comprises a lower amount of carbon than the inner layer region of the same;
• the inner layer region comprises a Ti-base carbide which has an average grain size of not less than 1 μm and which is dispersed in the inner structure to have an area fraction of not less than 0.1% to not more than 20%, whereas the outer layer region, having a layer thickness of not less than 0.05 mm, comprises a lower amount of Ti-base carbide than the inner layer region;
• there can be observed an area fraction of less than 0.1% of the Ti-base carbide, having an average grain size of not less than 1 m, at the surface of the sintered Ti-base material product;
• and
• the surface hardness is higher by 15% than the inner layer region.