Metal components may be made by either investment casting or sand casting, both of which involve pouring molten metal into molds. Since investment casting and sand casting both have their uses, it would be unfair to compare them and declare one superior to the other. We are often asked by our clients as investment casting producers what sets investment casting apart from sand casting. You can read an article that compares the two rapid casting methods here.
Investment casting, often known as the lost wax technique of casting, is a precise casting procedure used to create components out of any cast alloys. When it comes to investment casting, aluminum is often used to make the mold or pattern. The first step in investment casting, also known as lost wax casting, is to create a wax pattern by injecting wax into a casting mold until the desired shape and size is achieved. Finally, a ceramic casing is formed by immersing the tree assembly into a refractory slurry. Casting blanks are created by pouring molten melton metal into the shell via the sprue gate and letting it cool. Investment casting has several benefits, including:
- With investment casting, even intricately shaped components may have very thin walls.
- Extremely uniform net shape molded to exacting specifications.
- Superior surface finishes reduce the need for further processing.
- Duplex alloys, in addition to ferrous and nonferrous metals, may be employed.
- When producing in large quantities, investment casting may save a lot of money.
In sand casting, the sand is used to make the mold. Sand molds are more forgiving than metal or plastic ones as the molten material cools and solidifies, preventing cracks, tears, and other defects. Sand casting has several benefits, including:
- Particularly for smaller production runs, sand casting might be more cost-effective.
- It has enough of room for even the largest castings.
- Additionally, both ferrous and non-ferrous metals may be used in sand casting.
- Tooling expenses might be reduced after casting.
Investment casting vs. sand casting prices:
Inevitably, the investment casting method will cost more than sand casting would due to the added complexity and extensive preparation required.
When compared to sand casting, investment casting is superior when it comes to producing lightweight, complicated items weighing less than 1 pound. Sand casting’s size and weight constraints also apply to investment casting. In most cases in the United States and Europe, the maximum weight for a component that may be cast at a given facility is 20 pounds due to the limitations of the mold-handling machinery. Our China-based foundry for investment castings has the capability to produce castings weighing up to 120 pounds.
A further notable distinction between investment casting and sand casting is the surface polish. By using an aluminum template, investment casting may produce a completed product with smooth surfaces and tight tolerances. Delivering the casting blank is the penultimate step after sprue gate removal and shot blasting. In sand casting, the finished product is released from the mold by cracking it open. Therefore, the severing line will be drawn beyond the boundary of the final cut. Further, the abrasive sand will cause the surface of the completed cast components to be similarly rough. Therefore, subsequent machining to eliminate the partling line and provide a smoother surface will incur additional time and expense.
The simplicity of its layout:
Since the investment casting technique involves forming a ceramic shell mold with a liquid slurry, engineers have an unprecedented amount of leeway in designing components with intricate details and complicated forms. Sand casting components are often tapered (with draft angles) or contoured to reduce friction during removal from the sand. Making components with interior spaces or cavities is difficult for sand casting as well. In order to make the inside of an item using sand casting, cores must be put into the mold in the correct shape. It takes time to develop and secure many cores inside each mold, and there may be instances when more than one core is required.
When compared to other forms of casting, investment casting often produces better results, especially in terms of surface finishes. After more than two decades in business, the Chinese firm rapid tooling foundry has perfected the art of producing investment castings that are both reliable and up to international standards (the company is accredited by ISO). Moreover, we also provide sand casting service for those who need it. With the use of CMM, high-precision machining, and magnetic particle inspection, we guarantee that your castings will be free of defects and accurately sized. If you need a cast part and have an RFQ, please get in touch with us right away.