Experimental study of diamond turned quilt formation in metal foams and using simulated pores

Sandwich structures used to lightweight telescope mirrors result in subsurface pore or cell-induced surface deformation (called quilting), the unsupported sub-surface regions, during diamond turning of optical surface. An alternative sandwich structure is metal foams made by melt route which have a monolithic porous-nonporous interface naturally formed gravitationally induced drainage effect. This work compares effect pores on quilt formation A357 and Al 6061 foams, while also studying influence size cutting speed quilting using simulated controlled diameter single-pore samples 6061. Results show that height observed foam more than foam. Quilting with 0.89 µm appeared turned corresponding 3.87 mm when thickness nonporous region reaches 140 µm. In foam, 0.97 peak at 100 2.25 pore. The measured heights are normalized their radius, material strength reported. Simulated studies Al6061 both significantly formation, indicating optimizing conditions can reduce effects. study facilitates effective adoption for mirrors.