A valve component for a faucet includes a substrate comprising a base material and a strengthening layer provided above the substrate in an amount sufficient to improve abrasion resistance of the substrate, the strengthening layer comprising tantalum. A layer including amorphous diamond is provided above the strengthening layer. The amorphous diamond has sp3 bonding of at least about 40%, a hardness of at least about 45 GPa, and an elastic modulus of at least about 400 GPa.