Study on geometrical and dimensional changes in isothermal precision forging with complex shape during air cooling process

摘要

A series of experiments were made to analyse geometrical and dimensional changes of annaluminium alloy ring seat during the air cooling process. Geometrical and dimensional changesnwere measured by a structured light scanner. The corresponding microstructure evolution ofn7A09 aluminium alloy was characterised using thermal simulating experiment, X-ray diffractionnand transmission electron microscopy. Experimental results indicate that geometrical andndimensional changes are closely correlated with the shape of isothermal precision forging duringnthe air cooling process. The main reasons for distortions are non-uniform thermal field in thenworkpiece and inhomogeneity of the coefficient of thermal expansion caused by thenmicrostructure evolution.