Tech Talk
How can I overcome "Warping in a Thin Workpiece"?
Particular care must be exercised when sparking out on thin parts. Sparking out relieves the grinding forces on the grinding wheel, but also may generate a great deal of heat due to the scrubbing action of the cut. It is not unusual for a workpiece to be reasonably stable during the grinding but on spark-out will distort up into the grinding wheel due to the heat input causing the material to warp. This is particularly so with superalloys and heat sensitive materials.
Clamping methods may assist the situation. Clamping the part tightly may induce high stresses due to the restraint of the part. A clamping method which may overcome this is to clamp in a "free state".
The workpiece is placed on a magnetic table and a set of blocks or keepers, made from steels, are placed around the workpiece. Once the table has been magnetized, the keepers will prevent the part from skidding and hold it in position for grinding. A sharp wheel is essential at all times with plenty of cutting fluid flow.
