Metallurgical Factors Related to Machining Aluminum Castings

Three metallurgical factors have a major influence on the machinability of aluminum castings: chemical composition, heat treatment, and foreign inclusions. Othermet-allurgical factors that may also affect machinability are generally related to one of these three items. In general, aluminum alloys have good machining characteristics, although tests indicate that they cover a range. Some of the differences that do exist are discussed and practices identified that lead to improved machinability.