plating, anodizing, & finishing Q&As since 1989
Machining Techniques for Milling Nickel Chrome Plating on Aluminum
September 22, 2008
I'm looking for machining "best practices" for milling nickel chrome after it has been plated to an aluminum casting. I'm experiencing plating separation from the casting.Ron Farr
Buyer - Milwaukee, Wisconsin, USA
September 23, 2008
Hi, Ron. The chrome plating is measured in millionths of an inch, and would be destroyed by any milling, so I'm assuming you are milling an unplated area of the casting or an area that does not require plating.
Even in the best case the adhesion of plating onto an aluminum casting is problematic since it involves an immersion deposit of zincate onto a surface that is not wholly aluminum. So I think your first step in establishing "best practices" may be to conduct an adhesion test and to quantify what adhesion level is satisfactory. Good luck.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
October 3, 2008
The shear strength of nickel is on the order of 200,000 psi. Its bond strength to the aluminum on the order of 20,000 at best. What happens? The nickel prefers to separate than to be cut. Try with diamond or ceramic tools, high speed and light cut. G. Marrufo-MexicoGuillermo Marrufo
Monterrey, NL, Mexico