For designers who have traditionally expected dull, unattractive and pitted surfaces of traditional metal injection molded and die-cast parts, seeing the gorgeous as-cast surface of a Liquidmetal part comes as a shock. Liquidmetal parts have a shiny metallic luster straight from the mold without the need for time-consuming and costly secondary operations.
Liquidmetal alloy’s beautiful finish begins with using high purity alloy feedstock provided by one of the world’s leading metallurgical companies, Materion Brush. Liquidmetal Technologies then feeds that alloy into its own proprietary high purity vacuum injection molding platform.
Processing Liquidmetal under a vacuum prevents unattractive oxide layers from forming on the surface of the parts. At the same time, the vacuum eliminates the possibility of gas entrapment in the mold cavities, thus avoiding the dimple shaped defects commonly found in die-cast parts. Metal injection molded parts on the other hand, must be sintered after they are cast to burn off the polymer phase which holds the metal particles together. The resulting fused metal is grainy and dull, hardly suitable for cosmetic parts. Since Liquidmetal does not use binders, only pure Liquidmetal, the cast part is smooth and lustrous without the need for secondary polishing operations.
In traditional machining, on the other hand, achieving an aesthetically pleasing finish requires taking finish cuts or post processing such as polishing, lapping or grinding (see surface roughness comparison chart at the end of this post for details). These secondary operations add cost to the final part and increase the manufacturing time. In contrast, the molds used to make Liquidmetal parts only need to be machined and polished once. With each subsequent cast, the smooth surface features of the mold are replicated for every molding cycle of the machine. For machined parts, costly finishing operations are required for every single piece that is manufactured.
Since Liquidmetal alloy’s as-cast finish is aesthetically appealing, Liquidmetal can be used for cosmetic external parts and for internal parts requiring a smooth, clean finish. At the same time, Liquidmetal’s surface quality makes the parts more useful. Liquidmetal part surfaces are able to mate precisely with other part surfaces in applications which require tight surface contact.
Finally, a beautiful as-cast finish is only as good as how long it lasts. Traditional polycrystalline metals tend to get dented, scratched, worn and oxidized over time. Liquidmetal’s naturally superior strength, wear, scratch, and corrosion resistance resulting from its amorphous structure will ensure a Liquidmetal part retains its beautiful finish indefinitely.