Precision forging

Abstract

The manufacture of forgings to precise dimensional form and with specified mechanical and metallurgical properties has been the aim of industry since the industrial revolution. Developments towards this objective have been continual over the years as companies have sought commercial advantage in markets where competition from other industries such as foundry, powder metallurgy, sheet metal and fabrication is increasingly fierce. This paper starts with a brief review of historical milestones in the development of forging up to the first half of the twentieth century. The last 50 years have been a period of great activity in the establishment of a science base for forging technology and the development of cold, warm and hot processes with associated equipment to enable industry to provide components of greater complexity, increasing accuracy and nearer to net shape and research in the present author's laboratory has contributed to the advances in many areas. The major thrusts have dealt largely with improved tool designs and coatings for greater accuracy and longevity, techniques to enable metal to flow into die cavities of complex geometries and methods for complete process control, from raw material to product despatch. This paper attempts to highlight significant aspects of the technological developments which have been the result of world-wide activities. To give a coherent picture the steps of knowledge acquisition which have supported technological advancement are described using mainly the results of work from the present author's laboratory.