Characterization of machining damage in glass

Technical Report · Fri Nov 01 04:00:00 EST 1985

OSTI ID:6197689

Tsai, H

The material removal during diamond grinding of soda-lime glass appeared to occur by symmetric brittle chipping, probably due to lateral cracks. Indentation cracks in machined surfaces tend to exhibit irregularities at lower indentation loads and chipping at higher loads. The cracks are consistently smaller in size on the machined than the as-received specimens and no effect of annealing is noticeable. The moderate enhancement of resistance to strength degradation by machining occurs also when residual stresses are not involved. Therefore, the existence of machining-induced compressive residual stresses is not substantiated for glass. The indentation-induced residual stresses are observed in as-received glass. However, negligible precursor crack growth is measured during strength test of machined glass. Furthermore, the strengths of machined glass remain unchanged upon annealing after indentation. Thus, the residual stress effect about indentation is minimal in machined glass. A coherent explanation of these observations has been proposed.

• Research Organization: Lawrence Berkeley Lab., CA (USA)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 6197689
• Report Number(s): LBL-20512; ON: DE86006059
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
CRACKS
DAMAGE
GLASS
MACHINING
RESIDUAL STRESSES
STRESSES