This Small Business Innovation Research (SBIR) Phase I project aims to advance the cast-on technology for the metal casting industry to produce lightweight metal composite castings. Cast-on method is a cost effective method for the reinforcement of casting with dissimilar metals but suffers from defect formation such as de-bond, oxidation, and porosity at the casting/reinforcement interface. The project combines the merits of the cast-on method and the latest high-intensity ultrasonic processing. The use of high-intensity ultrasonic vibration technique in the cast-on process detaches oxides and bubbles at the surfaces of the insert, drives them away from the reinforcement/casting interface, and enhances the metallurgical interaction of the castings with the reinforcement metal. Furthermore, the grain size in the casting adjacent to the bond is reduced significantly. As a result, a strong and defect-free metallurgical bond is produced between the reinforcement insert and the casting.
The boarder impact/commercial potential of this project will be a breakthrough technology for the cast-on process and will increase the competitiveness of the U.S. metal casting, automotive, and defense industries in the global market, retaining or creating new jobs. This technology can be used to reinforce aluminum castings, magnesium castings, or castings of other lightweight materials for replacing heavy metal components for automotive, aviation, and defense applications, leading to significant energy savings, cost savings, and improved emission control. The U.S. transportation industry continues to focus on the increased use of lightweight alloys for weight reduction and energy savings. According to the data from the United States Automotive Materials Partnership (USAMP), a 15% weight reduction due to the use of lightweight components improves fuel efficiency by at least 10%. Decreasing fuel consumption by 10% reduces gasoline consumption in the United States by 10 billion gallons per year. This would translate into energy savings of 1,150 trillion Btu/year, a reduction of CO2 emissions by 200 billion lbs/year, and cost savings of $25 billion/year at current pump prices of $2.50/gallon.
Lightweight metals and alloys such as aluminum and magnesium have found increased applications in replacing iron and steels in automotive industries for weight reduction of the vehicles. Such substitutions, however, have often resulted in compromised performance and /or reliability. A well known solution to some of the performance and reliability problems associated with the use of light weigh casting materials as a substitute for cast irons and steels has been to provide high strength inserts at critical locations where severe wear or high stress is known to occur. Critical locations are defined as areas in a casting where the stresses or temperatures exceed the capabilities of the lightweight materials. High strength inserts can be placed at critical locations where severe wear or high stress is known to occur so that lightweight materials can be used for making the rest part of a casting for weight reduction. Inserts of expensive material can also be used at critical areas where severe corrosion is known to occur so that inexpensive material can be used for making the rest part of a component/casting. Cast-on method is a cost effective method for the reinforcement of a casting with dissimilar metals but it suffers from defect formation such as de-bond, oxidation, and porosity at the casting/reinforcement interface. This Small Business Innovation Research (SBIR) Phase I project entitled "Reinforcement of Lightweight Material Castings with Dissimilar Metals" aimed at developing an advanced USV-BondTM technology that can be used to achieve defect-free, high strength metallurgical bond between the high strength insert and lightweight material casting. Here, defect-free means that the bond is free from oxides, cracking, and porosity defects. The project has been successfully completed. A new cast-on technology, USV-BondTM technology, that is capable of producing defect-free metallurgical bond between dissimilar metals (steel inserts in aluminum casting) has been developed. Bond between dissimilar metals formed during a casting process using this new technology is 2 to 6 times stronger than that using the conventional cast-on method. Grain size in a casting adjacent to the bond obtained using our new technology is at least two to four times smaller than that obtained using the conventional cast-on method. It is expected that our new method is a cost-effective replacement of the conventional cast-on method for joining dissimilar metals using a casting process, which is considered to be the most cost effective method for joining dissimilar metals. This technology has excellent potential to be used commercially to reinforce aluminum castings, magnesium castings, or castings of other lightweight materials for replacing heavy metal components for aviation, defense, and automotive applications, leading to significant energy savings, cost savings, and improved emission control. The U.S. transportation industry continues to focus on the increased use of lightweight alloys for weight reduction and energy savings. According to the data from the United States Automotive Materials Partnership (USAMP), a 15% weight reduction due to the use of lightweight components improves fuel efficiency by at least 10%. Decreasing fuel consumption by 10% reduces gasoline consumption in the United States of America by 10 billion gallons per year. This would translate into energy savings of 1150 trillion Btu/year, a reduction of CO2 emissions by 200 billion lbs/year, and cost savings of $30 billion/year at current pump prices of $3/gallon.
