Investment castings are oftentimes termed as lost-wax castings in the industrial process. It is known as one of the oldest techniques for metal forming. Traditionally, the patterns for an investment cast were made possible by beeswaxes. Nowadays, high-technology waxes and refractory materials as well as specialist alloys are already considered in the procedure. This type of casting is relevant in allowing accurate and versatile varieties of metals and alloys.
One of the most recent advancement in investment castings is the lost foam casting. This type eliminates some of the steps in the entire process. On an overall consideration, the procedure is used for smaller casts but is able to produce complicated tasks such as door frames for aircraft and steel and aluminum castings. Although it entails lower costs for equipment, it is relatively more expensive than either sand or die casting systems. It also requires some minor surface finishing and machining.
The process behind investment castings
The whole process starts with the production of the so-called master pattern. The artist may use wax, clay, steel, plastic or wood to create the original pattern. After which, he will be ready to produce the mold or the master die. This one is made out of metal, steel or metal.
Once the molds have been done then the wax patterns will be produced as well. This type of pattern is not merely made out of wax. Plastic or frozen mercury are also being considered in the process. Patterns are done in two ways: first is where wax is poured into the mold and swished to produce even coating; and the other is through leaving the filled mold until it is cool and the desired thickness is obtained. When the wax patterns are removed from the mold then assembly should be done.
Of course, investment is an important part of the process. The ceramic mold itself is termed as the investment. This is produced by repeating three important steps in the process namely coating then stuccoing then hardening. After investing, dewaxing or drying comes next. This is usually done from a period of 16 up to 48 hours. Preheating, pouring and removal are also essential steps in the entire procedure.
Common applications for an investment cast
Investment castings are commonly applied in power generation as well as aerospace industries. They produce complicated shapes for turbine blades and are also important in making out cooling systems. Some of the common examples of blades produced from the process are directionally solidified, conventional equiaxed and single crystal blades. To some extent, military, medical, automotive and commercial fields also use investment casts.