We are a job shop that was asked to powder coat billet aluminum parts for a customer. The customer asked if the cure cycle will affect the physical properties of the billet aluminum?

Yes, the cure cycle can adversely affect the strength of the material. Peak substrate temperatures should be below 300°F--ideally 275°F. Aluminum billet material and/or alloys change crystal structure at about 410°F. The crystalline realignment at 410°F causes the previous ductile aluminum to become brittle.