Feasibility analysis of using machinable glass ceramics to manufacture non-contact measurement approach metrological artefacts

Rather than measurement contact methods, non-contact ones are more desirable in case of on-machine and in-process measurement due to their great accessibility and high acquisition rates. Nevertheless, it is well known that these methods commonly present different issues related to the surface properties of the digitized material and other external factors. Thus, an important characterization work must be carried out by exposing each non-contact technique to different conditions. For this characterization work, the use of metrological gage artefacts is mandatory. These artefacts must be made of materials on which non-contact methods will work properly. Therefore, the analysis of new materials is still an important issue nowadays. Among the current possible materials, those that can be easily formed in typical artefact geometries stand out, while maintaining the required properties such as low thermal expansion, high hardness, etc. In this work the feasibility of a machinable glass ceramic named Macor® to produce a metrological artefact to be used with a non-contact digitizing sensor is analysed. Once stated the benefits of this material and proposed some machining conditions, an artefact is manufactured and digitized with a non-contact laser triangulation sensor, comparing its results regarding to a widely used metrological reference system.