Hemker Wins 1994 Young Investigator Award By Ken Keatley Kevin Hemker has some advice for mechanical engineers: "Let's get small." He also has some words of wisdom for scientists who examine tiny specimens at the atomic level: "Think big." "Engineers designing for macroscopic properties need to think about the microscopic mechanisms that control them. And microscopists who count atoms need to think about what this arrangement means to real world problems," said Dr. Hemker, an assistant professor in the Department of Mechanical Engineering with a joint appointment in the Department of Materials Science. "It's an exciting challenge for me, both in the lab and the classroom." Dr. Hemker was recently granted a 1994 Young Investigator Award from the National Science Foundation. The award, which recognizes talented young researchers and extends them research support, provides each recipient with up to $100,000 a year for five years in federal and private funds. "The funding comes at an opportune time, because I'm now in the process of building up my lab," said Dr. Hemker, 32, who joined the Hopkins faculty a year ago. "Since the monies are not directly tied to one specific project, it gives us the freedom to work and grow in a wider range of research topics." Much of Dr. Hemker's research involves conducting mechanical tests and atomic-level observations of a class of materials called intermetallic alloys, which are used in the design of automotive, jet and rocket engines. His work is pioneering in that it combines the use of a high resolution transmission electron microscope with computer-generated image simulations, which are used to characterize these alloys more quantitatively than has previously been possible. "Intermetallic alloys are unique in that most of them grow stronger as the temperature increases, a property that is very desirable when you are designing engines," Dr. Hemker said. "We're trying to understand why they become stronger, and to do that we look at the atoms surrounding the defects in the crystal lattice of these alloys." In addition, Dr. Hemker is currently collaborating with scientists at the Swiss firm Castolin, which is involved in the development of thermal spray coatings, and at Orbital Sciences Corp., where launch vehicles for commercial satellites are being developed. "When scientists at places like Orbital Sciences build components for the next generation of launch vehicles, they want to know things like how strong the components are and how much the fuel tanks will shrink or expand when filled with liquid oxygen and hydrogen," he explained. "So we are conducting tests and doing those types of measurements for them." Dr. Hemker's primary goal at Hopkins is "to build an interdepartmental program that will teach students to bridge all the length scales that bound the theories and models describing materials behavior," he said. He is developing courses with the purpose of enabling students to have a fundamental understanding of microscopic mechanisms, and then apply them to real-world macroscopic problems. "Most technological advancements--jet engines to computers to everyday applications--are all limited by the properties of the materials that are being used," Dr. Hemker added. "There is a real need for mechanical engineers to understand and apply the fundamentals of materials science, as they are designing tomorrow's machines." But not all is work for Dr. Hemker. He's a regular participant, with a number of Materials Science graduate students, in Frisbee games on the lower quad. "One really nice aspect about the Hopkins environment is the fact that the student-faculty ratio is very low," he said, "because this gives me a chance to work with and get to know the students on a one-to-one level." Dr. Hemker also volunteers one night a week as a pastoral associate to the Catholic chaplain at the Johns Hopkins Children's Center. He previously spent four years as a volunteer chaplain at the Children's Hospital at Stanford. "Being around such courageous people and watching them deal with their hardships has a way of putting my own life into perspective," Dr. Hemker said. "Besides, the work at the hospital gives me stronger ties to the Hopkins community."
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