Product Code: ICAL06_M1005

Machinability of Laser Heated Silicon Nitride Ceramics during a Turning Process
Authors:
Marian Jankowiak, Poznan University of Technology; Poznan Poland
Konrad Bartkowiak, Poznan University of Technology; Poznan Poland
Presented at ICALEO 2006

The Si3N4 ceramics, due to low density, very good wear, corrosion and heat resistance, is important material with many engineering and medical applications. However the high hardness (2125HV) and brittleness ceramics made serious difficulties of machining. Laser Assisted Machining (LAM) is currently developed and under research method of hard Si3N4 ceramics machining. It is a hybrid process of the machining, where the material is heated via laser irradiation and soft surface layer is machined by defined cutting edge of the wedges. In comparison with conventional machining this method significant increasing wedges durability. The research presented here shows results of hard Si3N4 ceramics machinability. It was evaluated by VBc wear indicator on the polycrystalline diamond (PCD) wedges, geometric structure and surface roughness parameters of machined ceramics. The conventional turning and laser assisted turning of Si3N4 ceramics was investigated. The wear intensity of PCD wedges was under significant temperature influence of machined layer during turning ceramics process. It was proved that Si3N4 ceramics geometrical surface structure after machined has strong temperature relation with surface layer. The structure is changeable from determine feed wedge in the range of low temperatures to random structure for the highest temperatures.