Through observing hard spots in aluminum die casting and analyzing production condition

the metallographic characteristics and types of hard spots have been identified

and origination of the hard spots was described.Aiming at different types of hard spots

a series of countermeasures from the aspects of process design improvement to strengthen production management were adopted

such as strengthening raw materials management

improving melting process design

selecting proper aluminum alloy furnace according to the product quality requirement

using ceramic filter and rotary spraying refinery as well as adopting graphite crucible instead of cast-iron crucible in holding furnace

adjusting melting and refining process

strengthening worksite regulation.