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Vacuum impregnation seals leak paths that form during casting without changing a casting's dimensional or functional characteristics.

How Vacuum Impregnation Supports Environmental Responsibility

Jan. 13, 2021
Automotive casting production calls for aggressive efforts to eliminate waste and conserve resources, and manufacturers need to make their processes cleaner, safer, and more resource-efficient.

Automotive manufacturers recognize that operating with practices and technologies that are environmentally responsible and profitable are not mutually exclusive. Being environmentally responsible can achieve better growth, cost savings, improve brand recognition, and increase profitability. The environmental impact of the responsible use of resources is beneficial to everyone, and automotive manufacturers play a leading role.

Examples of manufacturers being environmentally conscious occur in all channels of the automotive supply chain. For example:
- Ford's closed-loop recycling manufacturing process. The OEM recovers enough aluminum scraps each month to produce more than 37,000 new Ford 150 truck bodies, all while consuming fewer natural resources and lowering energy consumption.
- Aluminum diecasting manufacturers are reducing their carbon footprint by adopting “green” aluminum. Green aluminum is manufactured using less carbon-intensive hydropower rather than carbon-intensive fossil fuels. Making one metric ton of aluminum with hydropower releases approximately two metric tons of CO2 equivalent, while making one metric ton of aluminum with fossil fuels releases up to 18 metric tons of CO2 equivalent.

Automakers and their casting suppliers can reduce waste and conserve resources further by implementing vacuum impregnation to correct casting porosity and surface defects.

Porosity. Whether it’s caused by shrinkage, cold shuts, inclusion, or entrapped gasses, porosity is inherent to the casting process. Interconnected porosity leads to defects, which are the leading cause of waste and scrap in casting production. This waste increases the carbon footprint of the casting process.

Vacuum impregnation. Vacuum impregnation is a low-impact method of sealing leak paths that form during the casting process. Specifically, vacuum impregnation seals the internal, interconnecting path of porosity that breaches the casting wall and may result in product failure. The technique seals the porosity without changing the casting's dimensional or functional characteristics.

Although there are many ways that vacuum impregnation aids manufacturers’ efforts to be environmentally conscious, three stand out:
1. Enabling design freedom
. To make parts lighter, casting design engineers specify aluminum alloys and thinner walls for critical components. Meanwhile, in order to achieve new design standards, these components have higher performance requirements and lower acceptable leak rates. These tighter requirements result in more parts being rejected and scrapped due to diecasting porosity.

Vacuum impregnation allows engineers to specify thinner, lighter designs while meeting quality standards without concern over the effects of porosity. The design freedom allows the engineers to develop better-performing and fuel-efficient vehicles.

2. Maximizing part usage. Porosity in castings robs manufacturers of the opportunity to move 100% of their parts into production. A 15% "fall out" of manufactured parts means that 15% more aluminum castings will be scrapped, and profits will be erased. The vacuum impregnation process allows manufacturers to use castings that otherwise would have been scrapped.

3. Eliminating melting and re-manufacturing. Vacuum impregnation eliminates the costly melting and re-smelting of material to manufacturer replacement castings. Vacuum impregnation also removes all the carbon and waste costs associated with trimming, blasting, machining, testing, and washing of replacement parts.

Each of these factors represents an opportunity to minimize waste, improve a manufacturer’s profitability, and positively impact the environment.

Automotive manufacturers and their suppliers must continue to be aggressive in their efforts to eliminate waste and conserve resources, in order to compete now and to grow their enterprises. In that light, manufacturers should look for other opportunities in their production processes to be cleaner, safer, and make more efficient use of resources. One of those opportunities is vacuum impregnation. It assists manufacturers to reduce production waste dramatically and control their resources by returning nearly 100% of parts to the production line.

Andy Marin is the marketing coordinator for Godfrey & Wing, a developer of vacuum impregnation technology. Contact him at [email protected]