Abstract
Experimental techniques for measuring temperature fields at the tool-chip interface during machining and in the workpiece subsurface during grinding are described. Both techniques involve measurement of the radiation emitted by the region of interest using a Charge-Coupled Device (CCD) based Infra-Red imaging system, yielding non-intrusive full-field in-situ measurement of temperature at high spatial and temporal resolution. In the case of machining, a key element in the measurement technique is the use of an optically transparent sapphire tool, which has enabled direct images of the tool-chip contact area in the infra-red. Principal characteristics of the temperature field such as the variation of temperature with position along the interface and the location of the region of highest temperature are identified. The implications of this measurement to the understanding of the tool-chip interface at the micro-scale are briefly discussed. In the case of surface grinding, the technique involves measurement of the radiation emitted by a side of the workpiece immediately adjoining the wheel-workpiece contact region, providing an accurate estimate of the in-situ surface and sub-surface temperatures in the workpiece. It is shown that by appropriate analysis of the temperature data, the heat flux profile in the grinding zone and the contact length between the wheel and workpiece can be estimated. Results indicate that the shape of the heat flux is triangular and that the actual contact length is greater than the geometric contact length.
