Brass Die Casting

high pressure die castingCasting is an object made in the die casting process. The metallurgical process is done with different alloys, among which brass is one. Copper alloy castings (brass castings) have the highest corrosion resistance as well as mechanical properties of all die-cast parts. Owing to the high metal temperatures as well as shorter mold life, brass in die casting has not been accepted readily as a good alloy. Of the die-cast brass alloys, the yellow brasses are subjected to the metallurgical process the most often. The benefits of brass casting parts, as with other alloys used in die casting, comprise good surface finish, accurate dimensional control, as well as high production rates.

In brass die casting, the induction brass melting is preferred usually. It will create less melt loss via dross formation, quicker melting, better brass composition control and temperature control, and less absorption of gas by the metal. The brass melting process’s speed is also significant, to reduce volatile alloying elements’ vaporization. It pertains especially to zinc, one of the alloying elements of brass.

Fluxes are not necessitated all the time in melting brass alloys in die casting. As dirt is present and unavailable, some fluxes may still be advisable in order to ensure the molten brass metals’ cleanliness. A typical flux consists of anhydrous borax’s three pounds and silica’s one pound per a hundreds pound of the brass metal.

Brass die casting with high pressure produces repeatable and intricate shapes at competitive costs. Some brass die casters operate cold chamber equipment that ranges from four-hundred to seven hundred and fifty tons in capacity. Besides, fully automated cells are also available at their disposal for heavier components or higher volumes required by the client.

Whether melting for the die casting of brass is done under either oxidizing or reducing conditions, it is advisable to maintain the absorption of gas at a minimum since the absorbed gas has to be removed before pouring. When the melting process is performed in a neutral environment, a protective cover (typically, charcoal) has to be employed to prevent oxygen and hydrogen’s further absorption. Dissolved hydrogen is eliminated from the molten metal by blowing inert gas into it. This inert gas is typically nitrogen. The dissolved hydrogen in the melt is diffused into inert gas and leaves it with the bubbles. This process is called “degassing”.

The cold chamber units used to die cast other alloys used in the metallurgical process are appropriate for brass alloys. The pressures of the die casting ram range from 3,000 to 10,000 pounds per square inch. The die casting plunger’s speed may differ from 10 to 250 pounds per square inch. The regulation the speed, pressure, venting, gating, as well as die temperatures are basically the same and influence the die castings’ quality, as with zinc and aluminum die castings.

The surface finish upon the mold cavities has to be matte or satin for the surface tension purposes. To die cast thin-wall components, a mold life of 50,000 shots or so can be expected in yellow brass castings or parts. For alloys that require higher metal temperature, it can fall to 10,000 parts.

Important Features of Brass Die Casting

In die casting brass, the mold life is usually given more consideration than the surface finish of the die-cast part. If temperatures are way too low, then scrap parts are made. When the die temperature is way too high, it will lead to blistering. Usual die casting mold, as well as core temperatures, are amid 600F and 1300F. Water or oil is usually circulated through the metal die to control the temperatures. The die lubricant is only sparingly used in brass die casting, because of the tendency of it to burn into the brass casting, leading to defective outputs. Graphite and/or oil is generally used on the tips of the plunger or where the release of the casting is an issue.

The scaling of the metal dies used in brass die casting is general and the die should be ejected from the casting equipment (maybe every eight hours) as well as polished. The repeated cleaning will result in dimensional changes, and where component dimensions are significant, machining of the brass casting or part may become essential.

The most significant factors in the production of brass die cast parts are weight, shape, quantity, as well as possible replacement orders, for giving an informed quotation. The die casting defects, misruns, excessive porosity, as well as flow lines are some of the pitfalls in the process. Therefore, die casters at Pacific Die Casting vie to achieve a proper balance of the brass temperatures, the die temperature, gating, and venting to resolve or eliminate the issue.

Some benefits of the brass castings are as follows:

  • Greatly corrosion resistant, which makes them perfect for marine applications.
  • High electrical conductivity
  • Temperature resistant
  • Pressure tight to three-hundred PSI
  • Easily plated or polished.

The copper alloy outputs cannot be as price-competitive as zinc, magnesium, or aluminum castings. However, copper alloy might offer a superior output at times.

Brass die casting produces a part with:

  • High strength
  • Corrosion resistant
  • Heat resistant
  • High conductivity
  • Beautiful look
  • Complex and precise shapes in high quantities at low prices

Examples of PDC’s Brass Die Casting Parts

Pacific Die Casting Corp. casts many fine brass light fixtures, brass door handles brass latches, etc. Requiring temperatures of approximately 1800 degrees Fahrenheit, brass die casting is often not within the typical die caster’s capabilities. However, Pacific Die Casting is knowledgeable and experienced in mold making and die casting with brass.