Subsurface Pore-Induced Quilting During Machining of Metal Foams

Abstract

Metal foams made by the melt route naturally have an interface region between the porous and nonporous structures. We investigate here the possible use of monolithic foam structures with such interfaces wherein the porous structure provides needed light-weighting while the nonporous region provides a functional surface such as the one needed for optics. Face turning is carried out in the nonporous region very near the interface to the porous areas. Using micro-computed tomography scans, pore positions are determined and the proximal effect of pores on the machined surface quilting effects are studied. Studies show that pore as near as 400 μm to the machined surface can cause significant quilting. Progress in developing finite element models to enable such predictions is also shown. This study could pave the way for the use of such structures for telescopic mirrors.