Jewelers Colored Base Metal Alloys for Casting and Rolling

Mid-States offers a variety of casting and rolling alloys for gold, silver. From standard casting to stone-in-place alloys, Mid-States has the alloy formulation that’s right for your production. 

A master alloy is a particular type of alloy designed to be added to a pure metal, in our case gold or silver, in order to modify its characteristics. A pre-master alloy is a master alloy from which a fundamental element has been subtracted

An alloy is a compound made up of two or more elements, of which at least one is a metal. The characteristics of an alloy such as hardness, strength and even color are generally different from those of the elements that constitute it

What characteristics can a master alloy act on? Once added to the precious metal, a master alloy can affect:

Color A feature especially requested by users of gold, whose color can be changed to pink, gray-white or various shades of yellow

Hardness Perhaps the most important feature, as gold and silver are relatively soft when in their pure state. The hardness is controlled through the master alloys both directly, with the simple addition of alloying elements, and indirectly, making the precious metal capable of undergoing hardening heat treatments.

Melting temperature Is another important parameter that in some applications it is useful to be able to control. Suppose we need to weld a joint, to do this we can use a particular alloy, which must melt at a lower temperature than the metal that forms the edges of the joint, in this way we will perform a particular type of welding called brazing. The control of the melting temperature is also important in the case of casting with wax setting of stones, where too high a temperature of the metal could irreparably damage the stones.

Size of the crystalline grain Using some elements called grain refiners it is possible to make the internal structure of the metal more compact, this greatly improves some aesthetic and technological aspects.

Fluidity Is an important factor especially in investment casting applications. It can be described as the ability of a liquid metal to faithfully fill an elaborately shaped pattern, such as a grid or filigree. Generally, the fluidity of precious metals increases as the casting temperature increases, but this can cause some side effects, such as interference between metal and refractory material, or evaporation of low-melting alloy elements. To overcome these problems, some elements, such as silicon, can be inserted in the master alloys for investment casting, which are able to increase the fluidity in the liquid state of the metal.

Shine Again for alloys dedicated to investment casting, using some elements it is possible to reduce the interaction between the liquid metal and the internal edge of the investment during the casting phase. The lower the interference, the less oxidized and opaque the surface of the objects will appear, which can be finished more quickly.

The advantages of the master alloy

Know-how The main advantage of relying on a master alloy is that the alloy manufacturer has a deep knowledge of the effect of the individual additions on the final result.

Reliability Furthermore, the producer carries out a selection and control work on the raw materials that allows to have constant results over time.

Simplicity The weighing of an alloy is easier and faster than that of various elements taken individually and the opportunities for error by the operator are reduced.

Stability The fineness of the precious material obtained is more constant because the casting process is simpler.

Technology Some elements (for example cobalt) are difficult to melt due to the high melting temperatures and their tendency to oxidation, therefore they require special machinery that is difficult to find in traditional laboratories.

Lower loss Melting the elements individually can lead to an increase in the decrease in title, when there are elements that evaporate at relatively low temperatures, such as zinc.

To conclude By relying on a specialized master alloy manufacturer, you can make gold and silver more than just precious metals, but real tools for making your creations.