How hard is hard chrome plating?
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Hardness Value of Industrial Hard Chrome Plating
Average hardness is in the range of 66 to 70 Rockwell C scale. A deposit of over 0.001-inch thick is essential before chromium will assume its true hardness characteristics when used over unhardened basis metals.
Then, is chrome plating hard?
Hard chrome plating is an electroplating process in which chromium is deposited from a chromic acid solution. Thickness of hard chrome plating ranges from 2 to 250µm. Micro-cracked chromium has a Vickers hardness of 800-1000 kg/mm 2, while crack-free chromium has Vickers hardness between 425-700 kg/mm 2.
Then, what are the problems of hard chrome plating?
Hard Chrome Plating Defects:
- Dull / milky deposits: There are a number of potential causes for poor chrome appearance, but it is most commonly caused by a mismatch in current density and bath temperature.
- Burnt deposits:
- Poor or partial coverage:
- Poor adhesion:
- Roughness:
- Pitting:
- Excessive micro-cracking:
- Mud Cracking:
Hard chrome plating leaves a layer of chrome from 0.0008 to 0.0050 in. (from 0.020 to 0.127 mm) thick on the surface of the metal. In contrast, thin dense chrome plating has a thickness from 0.0002 to 0.0006 inch (0.005 to 0.015 mm). The thickness of chrome plating varies depending on the application.