Johns Hopkins Gazette: September 12, 1994


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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