Pump with wear-resistant barrel and plunger having coating support

A pumping mechanism comprising:

• a barrel formed of a barrel substrate and having a bore;
• a plunger formed of a plunger substrate and slidably disposed within the bore in the barrel, the plunger substrate being nitride-hardened to a depth of between 20 and 150 microns below an outer surface of the plunger;
• and
• a coating disposed on the outer surface of the plunger, the coating comprising a tribological material,
• wherein each of a first end surface of the barrel and a second end surface of the barrel is coated with a metal plating.

A pump comprising:

• a mounting surface;
• a pumping mechanism connected to the mounting surface, the pumping mechanism including:
• a barrel formed of stainless steel and having a first end surface abutting the mounting surface, a second end surface opposite the first end surface, and a bore, each being coated with a nickel plating;
• a head formed of stainless steel and abutting the second end surface of the barrel;
• a plunger formed of stainless steel and slidably disposed in the bore in the barrel, the plunger having a Rockwell C hardness of at least 60 HRC to the depth of between 20 and 150 microns below an outer surface of the plunger;
• and
• a coating disposed on the outer surface of the plunger, the coating comprising diamond-like carbon (DLC).