Goodrich Corporation's Advanced Sensors Technical Center sent EPI's lab in New Berlin, WI samples of Kovar parts for blackening.
Their challenge was that the traditional stainless steel blackening of 416 series was more grey than black. Kovar contains a high amount of nickel 29% and cobalt 17% metals. Larry Abbott tried our Ultra Blak 466, hot black oxide process for nickel. Attached is an SME picture taken at 10,000x magnification. Goodrich likes the uniform black color because it was black with no grey which works better for their light sensor applications.