Towards predicting removal rate and surface roughness during grinding of optical materials

Journal Article · Wed Mar 27 00:00:00 EDT 2019 · Applied Optics

DOI:https://doi.org/10.1364/AO.58.002490· OSTI ID:1542715

Suratwala, Tayyab ^[1]; Steele, Rusty ^[1]; Wong, Lana ^[1]; Miller, Phil ^[1]; Feigenbaum, Eyal ^[1]; Shen, Nan ^[1]; Ray, Nathan ^[1]; Feit, Michael ^[1]

---

1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

A series of controlled grinding experiments, utilizing loose or fixed abrasives of either alumina or diamond at various particle sizes, were performed on a wide range of optical workpiece materials [single crystals of Al₂O₃ (sapphire), SiC, Y₃Al₅O₁₂ (YAG), CaF₂, and LiB₃O₅ (LBO); a SiO₂-Al₂O₃-P₂O₅-Li₂O glass ceramic (Zerodur); and glasses of SiO₂:TiO₂ (ULE), SiO₂ (fused silica), and P₂O₅-Al₂O₃-K₂O-BaO (Phosphate)]. The material removal rate, surface roughness, and the morphology of surface fractures were measured. Separately, Vickers indentation was performed on the workpieces, and the depths of various crack types as a function of applied load was measured. Single pass grinding experiments showed distinct differences in the spatial pattern of surface fracturing between the loose alumina abrasive (isolated indent-type lateral cracking) and the loose or fixed diamond abrasive (scratch-type elongated lateral cracking). Each of the grinding methods had a removal rate and roughness that scaled with the lateral crack slope, sℓ (i.e. the rate of increase in lateral crack depth with the applied load) of the workpiece material. A grinding model (based on the volumetric removal of lateral cracks accounting for neighboring lateral crack removal efficiency and the fraction of abrasive particles leading to fracture initiation) and a roughness model (based on the depth of lateral cracks or the interface gap between the workpiece and lap) are shown to quantitatively describe the material removal rate and roughness as a function of workpiece material, abrasive size, applied pressure and relative velocity. This broad, multi-process variable grinding model can serve as a predictive tool for estimating grinding rates and surface roughness for various grinding processes on different workpiece materials

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC52-07NA27344
• OSTI ID: 1542715
• Alternate ID(s): OSTI ID: 1503358
• Report Number(s): LLNL-JRNL-780620; APOPAI; 972565
• Journal Information: Applied Optics, Vol. 58, Issue 10; ISSN 1559-128X
• Publisher: Optical Society of America
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE