Brittle materials grinding

Ultrasonic machining, also known as ultrasonic impact grinding, uses ultra-sonically induced vibration delivered to a tool to create accurate cavities and channels of many shapes [146]. It can be used to form deep cavities as small as 250 pm in diameter (with an accuracy of 50 pm) in both hard and brittle materials such as glass, quartz, polymers, ceramics and metals. This technique may be useful for fabrication of large masters. 

Attrition force causes size reduction by friction contact of particles between them, with the grinding media as well as with the mill shell, and subsequent abrasion. It is effective for brittle materials of relatively small particle size. Rod and ball mills are mainly based on this force. 

The common removal mechanisms in grinding can be divided into ductile material removal and brittle material removal. For ductile materials,... 

Chip Formation (Abrasive Process), Fig. 2 Brittle material behavior versus ductile material behavior in grinding (based on Salje and Mohlen 1987 Klocke 2009)... 

Usually, grinding of hard and brittle materials causes microcracks which deteriorate surface quality. Thus, the transition from brittle-to-ductile material removal is considered to be of great importance for ultraprecision grinding. Much research effort has been spent to identify this transition and to understand the removal mechanism. 

Metal bonding can be separated into two different types sintered metal bonding and electroplating. In ultraprecision grinding the sintered metal bond system is used for thin wheels which cut brittle materials, for example, silicon wafers (slicing/dicing) (Anderson et al. 2001) or for micro-pencil grinding tools (Aurich et al. 2009). 

Aurich JC, Engmaim J, Schueler G, Haberland R (2009) Micro grinding tool for manufacture of complex structiu-es in brittle materials. Ann CIRP 58(1) 311-314... 

The total grinding energy E, required for brittle materials is the sum of the energy for brittle grinding Ef and the energy for ductile grinding Ep. Out of Eb, Ef is expressed as... 

Bifano, T.G., Ductile-regime grinding of brittle materials, PhD dissertation, NCSU (1988) 153. 

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