Experimental Investigation of Subsurface Damages Made by Cup Grinding and Lapping Process of Optical Glass BK7 in Ductile Mode
الموضوعات :
Vahid Barahimi
1
(Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran)
Masoud Farahnakian
2
(Department of Mechanical Engineering, Najafabad Branch, Islamic Azad University, Najafabad, Iran)
الکلمات المفتاحية: Optical Glass BK7, Cup Grinding, Subsurface Damages, Ductile Grinding,
ملخص المقالة :
Conventional material removal of BK7 optical glass will normally result in brittle fracture at thesurface, generating severe subsurface damage and poor surface finish. Subsurface damages inducedby grinding strongly influence the mechanical strength and optical quality of optical glasses.However, through ductile mode grinding it is possible to reduce the surface and subsurface cracks.It is meaningful to evaluate the depth of subsurface cracking through the measurement of surfaceroughness under different grinding parameters. In this research, the surface and subsurface damagesduring micro cup grinding and lapping process of optical glass BK7 are being investigated. In orderto invest the subsurface damages, cross section polishing method is being used and the crosssections are inspected through SEM microscope. The results indicate that number of subsurfacemedian cracks after lapping process are strongly decreased and surface lateral cracks are extendedall over the sample's ground surface.
