Patent ID: 8807075

Claim:
A shutter disk having a tuned coefficient of thermal expansion, comprising: a body having a top surface, a bottom surface, and a peripheral surface coupling the top surface to the bottom surface, the bottom surface having an outer step adjacent the peripheral surface, an inner step adjacent the outer step, and an annular groove formed in the bottom surface, wherein the inner step is disposed radially inward of the outer step and the annular groove is disposed radially inward of the inner step, wherein a thickness of the body increases from the outer step to the inner step, wherein the body is formed from a first material comprising aluminum and silicon provided in a ratio of aluminum to silicon of about 1:4 to about 7:3, and wherein the ratio of aluminum to silicon provides coefficient of thermal expansion of the body that is substantially similar to a coefficient of thermal expansion of a second material comprising titanium (Ti) to be deposited atop the body.