Influence of Quenching Process on Solution Treatment and Hardenability of SiCp/2009Al Composites

The quenching process and hardenability of the SiCp/2009Al composite are investigated from the perspectives of quenching media, medium temperature, and transfer time using the end-quenching method (Jominy test), combined with Brinell hardness measurement and scanning/transmission electron microscopy (SEM/TEM). The results show that when the transfer time and medium temperature are the same, compared with the samples quenched in 20%(volume fraction) polyalkylene glycol (PAG) solution, the sample quenched in the 10% PAG solution has fewer residual precipitates, with a content of 0.39%. When the quenching medium is the 10% PAG solution and the medium temperature 25 ℃, the material achieves a maximum hardness of 145HB with the transfer time of 5 s. Under this condition, the hardness of the sample stabilizes at a distance of 6 cm from the quenched end, and after 5 days of natural aging, the overall hardness increases, with that of the quenched end reaching 153HB. Based on the 10% hardness loss criterion, the effective hardened depth of the sample is determined to be 2 cm.