Anodizing Aluminum Die Casting Parts
Normally,aluminum die casting parts are not suitable to anodizing since alloy contain too much silicon.The anodizing will turn to dull and incontinuity.We take advantage of new aluminum alloy and high quality tooling,which make die casting parts come with anodizing in different colour as aluminum alloy with low silicon composition does.
To accomplish the nice anodizing for aluminum die casting parts,the following procedure must be done.
DM32/DM6 is quite nice die casting aluminum alloy for anodizing.Al6060 and Al6061 can be die casted and anodized as well if mechanical property does not take into consinderation,such as tensile strength,because they can not be strengthened via heat treatment.
Core and Cavity material:8407(Cost is higher than common H13 or SKD61 ).The molten temperature of DM32 is higher than common die casting aluminum,so the聽core and cavity聽will get crack very soon if聽use common H13 steel.Moldbase is LKM SC50 instead of 45# steel.
Tooling design:The layout of overflow and sprue is totally different from other die casting aluminum.Normally,DM32 need more overflow than A380.Sprue position need to fully聽avoid torrent of molten alloy.
Surface聽roughness聽of Core and Cavity:It will be very very聽fine since DM32 contain聽much less silicon聽and fludity is not good.The soldering problem will happen if polishing is not good.
Recycled material,such as overflows,flashes, totally prohibited otherwise anodizing will be affected badly.
Mold hold up time need to be much longer than usual die casting.
Casting surface:It must need very fine sandblasting before anodizing in order to achieve integrity and continuity of Anodizing.
Machining:Sometimes,DM32 casting need a littile allowance in order to guarrante the anodizing quality while same normal die casting with聽powder coating聽do not need.