Intermetallic compounds are of great importanceas structural materials in gas turbine applications due to their physical andmechanical properties as high melting temperature, low density, high thermalconductivity and corrosion resistant materials. However ordered intermetallicsare brittle and cannot support tensile load in many applications. Because ofthis brittleness, the processing of these materials must be done in such a waythat cracks and other residual damage is at a minimum.

  Grinding is a high throughput process that wouldbe very useful in the shaping of these intermetallics. Itcan be considered as a multipoint machining process, with a distribution of toolgeometries (grain size, rake angle, etc) and process parameters (force, depth ofcut, etc). Due to the negative rake angle of the grinding wheel grits, thespecific cutting energy (energy consumed to remove a unit volume of material) ofthis process is higher than in other machining processes. Consequently thematerial is subjected to high plastic deformation and temperature gradients.Local temperatures at the very contact zone can be close to the melting point ofthe material.

  Variations in grinding parameters influence the surface and subsurface damage produced onthe material. This damage is the generation of surface and subsurface cracks andmaterial chip-out. Also the grinding process produces changes in the materialthat may be possible causes of future damage. These can be in themicrostructure, produced by the thermo-mechanical history, generation ofresidual stresses and a subsurface zone with plastic deformation.

  While the use of intermetallic compounds is very restricted in the electronicsindustry, the process of material removal and damage generation is closelyrelated to the one that takes place on silicon. The work at the EML intends torelate grinding parameters with the damage produced on TiAl and NiAl. Actualgrinding experiments are done using a surface grinder with equipped with a forcecontroller and a 3 axes dynamometer. Studyingthe fundamentals of grinding single point scratch tests are performed in alinear scratching machine, varying parameters as tip geometry, normal force,scratching speed and material cristallographic orientation in the case ofnon-isotropic materials.

Material damage information is obtained from the test results. Crack density, andorientation, as well as plastic deformation and microstructure changes areobtained using optical  and scanning electron microscopy. Plasticdeformation depth is obtained using the bonded sample technique.

Temperature at the zone of the scratching is obtained through a developed non-contactthermometer using a chalcogenide fiber optic to collect infrared radiation fromthe sample and an infrared detector to convert it to an electrical signal.
  FiniteElement Analysis (FEA) supports the experimental research on this area andallows us the possibility to formulate a sounded analytical explanation of thedamage generation