ON THE DEVELOPMENT OF SURFACE TEMPERATURES IN PRECISION SINGLE-POINT DIAMOND ABRASION OF SEMICONDUCTORS

This paper presents an analytical, variable-conductivity, thermal mode l for single-point diamond precision machining of semi conductors. The model is used to calculate the temperature development during the sim ulated machining of silicon and germanium wafers. The heat generated a t a tool-work piece contact is taken as the product of the coefficient of friction, the relative sliding speed, and the contact stress. Wher eas, heat partition between the diamond abrasive and the work piece is obtained through a modified Jaeger-Blok analysis that incorporates th e coupling of the thermal properties of the tool-work piece system. Th e results indicate that: for the ranges of nominal loads, cutting spee ds and feeds encountered, the work piece surface temperature rise is w ell below the thermal softening temperatures for these materials. This , has direct implications to the ductile removal mechanisms. The low v alues calculated for the work surface are shown to be consistent with several calculations based on the analysis of conventional machining. (C) 1997 Elsevier Science Ltd.