The advent of commercial grade picosecond and femtosecond lasers has opened the way for laser micromachining
of metals. There has however been no or little work reported on the ceramics. Use of diamond saws is still the
preferred way of cutting the ceramics such as an Al2O3-TiC composite (referred to as N58 hereafter) that is widely
used in the manufacture of read/write heads for magnetic recording hard disk drives. These read/write heads are
commonly referred to as "sliders".
We report here attempts to cut rows of sliders using various lasers. The cut length was 0.85 mm and the thickness
was 0.23 mm. We found that all the nanosecond pulse range lasers, left slag at the laser input edge of the cut and on
the cut wall. In many cases the slag deposit doesn't allow one to cut through the entire thickness as the slag
interferes with successive laser pulses.
Our best results were obtained with picosecond and femtosecond lasers. We were able to cut through entire
thickness of the strip with these lasers. The slag was much less than that from the nanosecond lasers, but not low
enough for our application. There were slag deposits or loose-appearing material on the cut walls also. The
roughness was at best in the micron range.
In all the cases studied the cut quality as measured by cut surface roughness and slag formation as well as the
cutting speed was worst than that obtained from the diamond saws currently used in the industry.