While metal casting might be the best process to manufacture a wide range of components, depending on your needs, a forging could be the best option. Or vice-versa. Here are 5 things to consider when deciding if a casting or forging is right for your component, application, and overall needs.
Which casting process should you use to manufacture your metal part? This is a common question when customers develop a new component or are considering making a switch to metal castings from a fabrication or forging. Partnering with a supplier that brings a full range of metalworking processes lets you be confident that you are getting the best metalworking advice and not just being sold on an idea because it is the only answer a supplier has.
In this article, we will cover various casting processes you might select based on your product design and needs in a simple, bullet point format.
NOTE: This article assumes you have a basic understanding of various casting methods. More specifically, sand casting, investment casting, and centrifugal casting.
Investment Casting (Lost Wax Casting)
Factors such as design requirements, cost, and feasibility to manufacture dictate which casting process is most suitable to manufacture a product. This article describing investment casting is intended to help you make an informed casting decision.
Investment casting produces precise components while minimizing material waste, energy, and subsequent machining. It can also ensure the production of very intricate parts. This makes the investment casting process quite useful to design engineers.
The goal is to understand what is meant by investment casting. So, What exactly is the investment in “investment” casting? The term “invested” historically carries the meaning of “clothed” or “surrounded.” Investment casting employs a shell made of ceramic, plaster, or plastic that is formed around a wax pattern. The wax pattern is melted and removed in a furnace and metal is poured into the shell to create the casting.
What is investment casting used for? Let's break down the investment casting production process for a greater understanding:
Partnering with a supplier that brings a full range of metalworking processes lets you be confident that you are getting the best metalworking advice – and not just being sold on an idea because it is the only answer a supplier has. The replacement of multi-piece weldments or highly-machined hogouts by single piece castings has been proven time and again to be one of the most effective ways to reduce real product cost. Here are just five real-life examples of when the casting process was a better choice for the customer than a fabrication or forging.
#1.) Centrifugal Casting Replaced Complex Fabrication
Controllable pitch propulsion (CPP) systems provide the ability to alter the angle of the ship’s propeller while in use, allowing for different performance during cruising and maneuvering. A centrifugal hub provides the strength and size needed to transfer up to 50,000 shaft horsepower to five attached propeller blades. The hub and 15 other accessories that MetalTek produces for the CPP must perform in corrosive environments for the life of the vessel. Fabrications previously used were very intricate, with multiple pieces and welds, and much machining. The single piece nickel aluminum bronze hub that MetalTek has supplied for 35 years is the largest, most complex centrifugal casting ever produced. The use of a single piece part in this application eliminates welded joints and defects in those fabrications that are only discovered after finished machining.
#2.) Fabrication Could Not Achieve Dimensional Stability
International research, including that done in conjunction with the DOE, strives to create conditions in the lab necessary to support nuclear fusion. Huge machinery, such as the “Z-Machine”, can create temperatures of 2.9 million °F (1.6 million °C) for fractions of a second. Integral components must have the ability to conduct electricity and perform in the machine’s water cooling system. Attempts to use fabrications in those applications were abandoned because dimensional stability could not be achieved. The customer came to MetalTek for a casting solution, a particularly challenging one because of the product’s large size. MetalTek specializes in large investment castings, and now supplies products with better dimensional consistency than was available with a fabrication.
MetalTek offers more metal casting process diversity. Your ability to source centrifugal, sand, investment, HPLT, or continuous cast products from a single company is not available anywhere else in the world. Not sure which precision casting process is right for your components or application? Read the below article on the basics of casting and feel free to contact us if you have questions. We would love to become your metals partner Because You Demand More Than Metal.