Mechanical Behaviour of Solution Heat Treated LM4 Alloy

LM4 alloy is a general engineering alloy containing majorly Aluminum, Silicon and Copper as the alloying elements. The alloy possesses good castability, low material cost and it is regularly used for many engineering applications where its moderate mechanical properties are desirable. While many investigations have been carried out on the alloy, only few studies have reported investigations on mechanical behavior of LM4 alloy processed at low temperatures. Therefore, this study investigated mechanical behavior of LM4 alloy material solution heat treated at 100ºC. LM4 alloy material was prepared in the laboratory and cast into rods of 15 mm diameter and 200 mm length. A sample of the cast rods was solution heat treated at 100ºC for 24 hours, while another untreated sample which served as control was also prepared. The samples were evaluated for mechanical behaviours on a Universal testing machine. Results showed that the solution heat treated LM4 alloy material exhibits superior mechanical behavior as compared to the untreated LM4 material. Microstructure of the solution heat treated alloy show some modified structure, however with decreased elongation. Solution heat treatment of LM4 alloy material at 100ºC for 24 hours, can be used to improve the mechanical properties of the alloy material. In general, solution heat treatment can induce a large number of submicroscopic particles with non-equilibrium transition structure which may strain the matrix of the alloy material to increase strength.