Post Machine Firing

Terminology

Peak temp

Time

Purpose

Clean

1200 C

1 hr

To burn off organics, usually to prepare for next step such as metallizing, etc.

Anneal

1350 C

1 hr

To heal microcracks induced from machining, lapping, etc. Minimal surface finish improvement, absolutely no grain growth will occur. Flatness is not compromised.

Refire

1535 C

1-4 hrs

To create a "glassy" surface. Some exaggerated grain growth will occur especially at longer soak times, flatness may be compromised if not careful, some additional shrinkage may occur, and surface finish will improve slightly