Effect of retrogression and re-aging on mechanical &wear properties of LM-25 aluminium alloy

• Published in: IOP conference series. Materials Science and Engineering 2021-02, Vol.1070 (1), p.12108
• Main Authors: Gopi Mohan, Ranjith, Jayasankaran, J, Ilangovan, S, Shanmugasundaram, A
• Format: Article
• Language: English
• Subjects: Ageing; Aging (metallurgy); Aluminum base alloys; Frictional wear; Grain structure; Hardness; Heat treatment; Impact tests; Ingot casting; LM 25; Precipitates; Retrogression; Sliding friction; Tensile strength; Wear rate
• ISSN: 1757-8981; 1757-899X
• DOI: 10.1088/1757-899X/1070/1/012108

The effect of retrogression and re-aging on the mechanical and wear properties of LM 25 were studied. The raw material ingot was casted in to cylindrical rods. The samples were solutionized at 530 °C for 2 hours and then artificially aged at 165 °C for 12 hours. The samples were heat treated using retrogression process at temperatures 200 °C, 225 °C, 250 °C, and 275 °C and re-aged at 165 °C for 12 h. The samples were tested for its hardness and tensile strength and found that the 200°C retrogressed and re-aged sample (HT1) was having high hardness (125 HV) and the tensile strength was recorded as highest (182 N/mm2) when compared to other samples. Izod impact test was conducted for all the samples and it remains same for all the samples. Dry sliding wear test results shows that HT1 sample was having least wear rate when compared to other samples.Microstructure of HT1 sample reveals that the silicon precipitates of sleek and finer grain structure, which improves the hardness and tensile strength.