Abstract
It is difficult to obtain a high degree of flatness on thin aluminum alloy plates because of residual stress by lapping. This paper reports on theoretical analysis of deformation of disks at various thicknesses. The residual stress is seperated into original stress due to lapping and secondary stress caused by deformation depending on thickness. Equations calculating the amount of deformation of circular plates using the former stress are then induced. Experimental results determined by measurements made while removing successive uniform thin layers in various lapping conditions show that depth of worked layers and distribution of residual stresses depend on grain size. Numerical values calculated by the above equations are in good agreement with flatness values on 70 mm diameter lapped model disks.
