In a method for producing a brake disc, a friction surface layer is sprayed onto the base body or onto an intermediate layer applied on the base body by cold gas spraying a particle mixture which consists 25 to 75% by weight of a metal matrix material and 75 to 25% by weight of a carbide material. The metal matrix material consists of an iron-based alloy, nickel-based alloy, titanium or titanium alloy. The carbide material consists of tungsten carbide, titanium carbide, iron carbide, silicon carbide, chromium carbide or niobium carbide.

Coatings that can be used on limited line of sight substrates are described. In some embodiments, the coating may be a metal alloy coating applied to an inner surface of an article such as a rod, tube or pipe. The inner surface can be present within a cavity of an article.

Shock absorbers that include a piston member configured to contact a functional fluid during movement of the piston member are described. The piston member can include a coating on a surface of the piston member. The coating can include a metal or metal alloy such as, for example, molybdenum or tungsten in combination with one or more other materials.

Rods and pipes that include a coated surface are described. The rod or pipe can include an alloy layer on a surface. The alloy layer can include molybdenum or tungsten and at least one element or at least one compound comprising one or more of nickel, cobalt, chromium, tin, phosphorous, iron, magnesium or boron.

Methods of preventing or reducing cutter loss in a steel body PDC drilling tool may include applying a hardfacing layer on a surface of a PDC cutter pocket to form a covered PDC cutter pocket, the hardfacing layer comprising a metal binder and coated tungsten carbide particles; and bonding a PDC cutter into the covered PDC cutter pocket with a brazing material. Steel body PDC drilling tools may include a steel body, a PDC cutter, a PDC cutter pocket, and a hardfacing layer. Methods of preventing or reducing cutter loss in a steel body PDC drilling tool may include applying a hardfacing layer on a surface of a PDC cutter pocket of the steel body PDC drilling tool; applying a coated buffering layer on the hardfacing layer to form a coated PDC cutter pocket; and bonding the PDC cutter into the coated PDC cutter pocket with a brazing material.

Metal work rolls that contact a functional fluid during movement of a rotatable body are described. The rotatable body can include a coated surface with a surface coating. The surface coating can include a metal or metal alloy such as, for example, a molybdenum alloy or a nickel alloy or a tungsten alloy. Systems and processes using the coated work rolls are also described.

Rotational devices that include a substrate with a coated surface are described. The coated surface can include an alloy layer with molybdenum or tungsten and at least one element selected from the group consisting of nickel, cobalt, chromium, tin, phosphorous, iron, magnesium and boron. Systems including the rotational devices are also described.

Pneumatic articles that include a moveable component with a coated surface are described. The coated surface can include a surface coating including an alloy layer that includes molybdenum or tungsten in combination with one or more other materials. Pneumatic cylinders and pneumatic devices are also described.

Hydraulic devices that include a moveable component configured to contact a functional fluid during movement of the hydraulic device are described. The hydraulic device can include a coating on a surface. The coating can include a metal or metal alloy such as, for example, a molybdenum or tungsten in combination with one or more other materials.

Reciprocating devices that include a moveable component configured to contact a functional fluid during movement of the moveable component are described. The moveable component can include a coating on a surface of the moveable component that contacts the functional fluid. The coating can include a metal or metal alloy such as, for example, a molybdenum in combination with one or more other materials. Pneumatic and hydraulic devices and devices are also described.