Evaluation of several lubricants for aluminum alloy forgings

Ring compresion tests were conducted to evaluate lubricities of 20 kinds of lubricants for hot forging of 2014 alloy at 250° to 450°C and 10 to 50% reduction of height. The lubricity was evaluated by comparing the respective friction factors. The lubricants dispersed in oil are spray coated on the die at elevated die temperatures more successfully than those in water or emulsion type lubricants. High purity and grain finess of graphite and properties of the base oil are important for lubricity of a colloidal graphite in oil type lubricant. Several types of lubricants reasonably selected are successfully used for aluminum precision forging.