Further evaluation of boric acid vis-à-vis other lubricants for cold forming applications

The effectiveness of boric acid as lubricant has been evaluated in ring forging and deep drawing operations. The elapsed lay-by time between boric acid coating preparation and forming operation has significant influence on the friction factor. Fresh surfaces provide least friction since longer lay-by time permits absorption of moisture from the environment and tend to increase friction. Forging speed has no effect on the performance of boric acid lubricant. The average of peak forces obtained with tools having different surface coatings indicated that the hardness of the coating also has no effect on the effectiveness of the boric acid lubricant.

► Fresh surfaces of boric acid lubricant layer provide least friction.
► Forging speed has no influence on the performance of boric acid lubricant.
► Performance of boric acid lubricant is better than that of Molykote but less than PTFE coating.
► Performance of boric acid is comparable to that of grease and graphite for deep drawing.
► Hardness of coating on the tool has no effect on lubrication.