LOCALIZED STRENGTHENING OF Al-BASED CASTING ALLOYS BY AUTOMATIZED OPTIMIZATION OF LASER HEAT TREATMENT

摘要

The mechanic properties of many Aluminum alloys can be changed by a heat treatment and quenching procedure. If locally a strengthening of the alloy is needed, a localized heat treatment and quenching procedure may be an alternative to the energy intensive and costly treatment of the whole part. However, it is not obvious which process parameters are required in order to achieve the desired local strengthening. Thus, a numerical simulation of local heating and cooling in combination with predictions of the material constitution and thus local property changes is used for a multicriteria optimization approach where the desired local strengthening is defined as target function. The optimization scheme performs a series of process simulations where laser power and exposure time are varied automatically until the effective process is found which ensures sufficient local strengthening of the alloy.