Allen Hunter
From Northwestern University Center for Atom-Probe Tomography
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| Research: | Copper Strengthened Steel Alloys |
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| Education: | Graduate Student, Ph.D. Materials Science, Northwestern University, 2011 B.S. Materials Science and Engineering, Michigan Technological University, May 2007 Minor: Metal Casting Enterprise, Michigan Technological University, May 2007 |
| Publications: | Publications by Hunter in our database |
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Contact | |
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Allen Hunter
Cook Hall Rm 1049
2220 North Campus Drive Evanston, IL 60208 Phone: 847-491-5946
Email: a-hunter@northwestern.edu
Fax: 847-467-2269
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The main strengthening addition of conventional steels is carbon, which forms various carbide phases that strengthen the alloy. However, an increase in carbide volume fraction is accompanied by a decrease in elongation and toughness due to the brittle nature of the carbides. Thus, a tradeoff exists between high strength and high toughness in carbon steels. Additionally, steel plate is typically joined by welding. The rapid cooling rate associated with the weld and heat affected zones tend to form martensite in high carbon steels. This phase is much more brittle than the steel substrate and will lead to brittle failure along weld lines unless expensive post-weld heat treatments are performed.
A way around these issues is to replace the strengthening mechanism. Copper has a low solubility in iron and forms nano-scale precipitates that effectively strengthen the alloy. The carbon level in the steel can be practically eliminated with suitable amounts of copper and other alloying elements resulting is a combination of high strength and toughness. Additionally, the steels are easily weldable due to the minimum carbon concentration.
A copper bearing steel alloy, designated as NuCu140 was developed at Northwestern to exploit the properties of the copper precipitates.
