Aluminum Die Casting Vs Zinc Die Casting

Comparing from aluminum die casting vs zinc die casting, their common ground is basic of die casting process. These process all require pouring the molten metal into the precision die and form intential shaped metal parts under high pressure, then passes some post-process methods to have some fine surface finishes. 

Aluminum Die Casting vs Zinc Die Casting : Material

Metal Alloys Cost

These Two types of metal alloy have sharply different material cost respectively. Aluminum alloys cost is even low, and easy to purchase, they can be get easily anywhere without specific purchasing. Depends on different applications of aluminum die casting parts, Die casting manufacturer will purchase different type of aluminum alloy to make various functional die casting parts. Like 7075, 6061,5052 and 2024 etc. However, zinc alloy cost is aluminum alloy three times even though more higher, what’s more, zinc alloys should be bought at specific metal composition factorties or recycle defective zinc die casting parts and zinc scraps. Zinc alloys include of the below types : Zamak Alloy and Aluminum Alloy.

Metal Alloys Melting points

The existed solid metal alloys should all be molten and made into useful die casting parts across many industries. but they allow different melting points and temperature. Aluminum alloys require higher temperature to melt, its melting point is up to 600 degrees due to aluminum element metal property. Therefore zinc alloys are newly metal composition material, is basic of zin element, added with other metal elements. Its melting point is comparable lower, which is up to 430 degrees due to zin metal property.

Conductivity

Aluminum Alloy and zinc alloy have all good conductivity. but there is a significant distnction between both. Whenever elctrical conductivity or thermal conductivity, aluminum alloy always priorer than zinc alloy. Most of Aluminum die casting parts are used for electronic components module housings and enclosures and connectors due to aluminum best conductivity. But zinc die casting parts are used for weight-ratio in automotive industry for overall cost cutting and cost- efficiency of cars. For example, transmission housings and balance weight brackets.

Corossion Resistance

The Two types of metal alloys have good corrosion resistance, and standwith strong corossion in atmosphere and liquid due to these matal can generate a oxide layer on the surface of it and protect it’s metal is continuously touched of corrossion substrict or oxygen gas in the air and damage its metal properties. From some proven experiments, Aluminum alloy corossion resistance is better than zinc alloy one. Aluminum alloy die casting parts have a longer life for physical applications because aluminum anodized layer is thicker than zinc alloy, and always protect the core metal property well, however zinc alloy, which can downgrade after they are used for long time due to the thinner anodized layer on part, even through in specific conditions, and the anozide layer maybe break.

Weight

Zinc alloy density is from 5.0~6.7 g/cm³， it is comparable heavier, almost equal to 2.5 times aluminum density, which is 2.7 g/cm³, and very light, and used for aerospace and military defense. Therefore, high volume zinc die casting parts have been used for automotive parts and aim to increase overall weight of vehicle and stead the vehicle performance.

Aluminum Die Casting Vs Zinc Die Casting: Process

Process Cost

Aluminum die casting has higher process cost due to high melting point metal and defective rate. From melting metal at the beginning, high energy consumption will increase the cost of die cast part. During casting metal part, long time cooling either enhance time cost or causes more defective parts. So its production effective rate is lower. In another one, aluminum die casting part surface often porosity status, which makes more post processes required in further. From aluminum die casting vs zinc die casting , Overall process cost for aluminum die casting is much higher than one of zinc die casting.

Zinc die casting needs lower temperature to cast high quality die casting parts. From melting metal at the beginning, less energy consumption and fast cast cycle lead to high efficiency mass production and high finished products production rate. What's more , zinc die castings superior surace finishing allows less post process. Zinc part is more easy to be plated and other surface finishing. It overall process cost is far lower.

 Energy Consumption

From aluminum die casting vs zinc die casting, aluminum die casting require more energy consumption than zinc one due to different melting points metal.

 Tooling Life

Aluminum cast die requires accepting higer temperature because melting aluminum temperature is high, up to 650 degrees or so. Therefore, zinc cast die accept low molten zinc temperature, up to 430 degrees, consistent running at high temperature environment for casting, its tooling life is shorter than lower temperature environment. So the cast die life for aluminum alloy is longer than zinc one .

Surface Finishing Options

There is often porosity on the aluminum cast parts due to aluminum alloy metal property. Added post processes is done for optimizing surface finish of aluminum parts, bonding a thin layer of zin on them exception for removing grease, dirt and burs. Then allows further surface finishing. But zinc cast parts can directly allow various coating treatment due to zin is one type of strong bonding metal material once clearing the surface of zinc cast parts.

 Process Defective Rate

Different process method generate different process defective rate. Aluminum die casting vs zinc die casting, aluminum die casting generate high volume defective cast parts due to aluminum alloy metal property.

Process Technique