<title>Dimensional stability of electroless nickel coatings</title>

Abstract

Dimensional instability in electroless nickel (EN) coatings is the result of two effects related to thermal expansion mismatch between the substrate and the EN coating: a continuous reversible contribution from the coefficient of thermal expansion (CTE) mismatch between the EN coating and the substrate and one or more one-time irreversible thermally-induced volume contractions of the EN. This paper presents a description of both mismatch components how each effects the ultimate stability of an EN-plated optic and which processing parameters can lead to improved stability.