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.
The days when manufacturers had a host of technical experts on staff are past in many industries. And this at a time when material choices are broader and product performance demands are higher than they have ever been. So the situation will not get any easier. Here are just four real life examples where MetalTek International helped a customer's heat, wear, or corrosion problem.
If you have a question about alloy selection, if you manufacture products that operate in harsh corrosive, high wear, or extreme temperature environments, or if you are simply looking to improve product performance, contact MetalTek.
#1.) Bearium Solves Load and Friction Problems in Mobile Crawler
From the days of Apollo program through the Space Shuttle a heavy duty crawler has carried the enormous weight of space vehicles down the one-mile path to the launch pad. Early designs used to carry this load were subject to sudden catastrophic failures of the roller bearings, jeopardizing timing of the launches. The crawler went through an emergency redesign to replace the roller bearings with sleeve bearings manufactured using Bearium B-10, a high-lead bronze that is only available from MetalTek International. Designs using Bearium delivered acceptable performance in an application that would then feature much higher friction. Bearium is used in the space craft crawler application to this day.
#2.) Creating a “Memorial to Last a Lifetime”
Working with architects to create a “Memorial to Last a Lifetime” is no small task. Every step of program management is critical—from materials and engineering, to budget compliance, to execution. Initially, the Pentagon Memorial team approached MetalTek International about choosing the “right” alloy to last 150 years; as various materials were trialed and budgeted, the ultimate selection came down to a restricted-range 316LN (CF3MN-Mod) alloy that would meet the design requirements and still be producible to tolerances such that 184 Memorial Units, each weighing over half a ton and measuring over 12’ (4m) in length, would seem to be “identical.” Specialized tooling, processing and fixtures were developed, trialed, and modified against an aggressive timeline. In the end, MetalTek met the Vision, the Budget, and the Schedule.
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.
There are often alternative ways to manufacture any given component. Sometimes the first way chosen to manufacture a component is not the best way. There may be a number of reasons for that. Perhaps one has an expertise or bias for machining, or welding, or forging, or casting, or assembly. Components may end up being produced in a way that is familiar and functionally adequate, but less than optimal in terms of performance, cost, or quality.
There may come a time in any product’s life when it makes sense to investigate alternative methods of manufacture. Such evaluation would be to convert a hog-out, forging, or multi-piece weldment to a single piece casting.
What makes a good conversion?
Among the factors to consider when deciding if a design is a candidate for a conversion to a casting are cost, quality, and performance.