Industry aims as diverse as getting more pop cans from a sheet of aluminum and making ever-smaller computer chips are being advanced with the help of a new arrival at WSU. A state-of-the-art field emission scanning electron microscope (SEM) is helping WSU’s David Field answer questions about the properties of metals and other materials that are valuable for a variety of industries, ranging from aluminum to semi-conductors.
Field, an associate professor in the School of Mechanical and Materials Engineering, is an expert in the crystalline structures that make up metal, ceramic and semiconductor materials. He recently received a grant from the National Science Foundation to purchase the high-resolution microscope.
With the SEM and instrumentation that is attached to it, known as an electron backscatter diffraction system, Field can investigate the directional nature of materials properties. This is done by shooting a beam of electrons into the crystal and viewing the pattern formed by the electrons as they “bounce” off of it.
Similar to the way in which someone standing in an apple orchard can see patterns in the trees’ alignment, researchers can use the microscope to see diffraction patterns created by the electrons as they exit the specimen surface. Understanding these patterns helps researchers understand and maximize a material’s properties, such as its strength, fracture resistance or formability.
Such information can be used, for instance, to help industry better know how good the interconnect structure of a computer chip might be and how long it will last. Having an understanding of a material at the atomic level is particularly important as computer chips and their components have continued to shrink in size.
With the SEM, Field can look at grains as small as 10 nanometers, rather than the 250-500 nanometers that could be seen previously on instruments at WSU. Leading companies in the metals industry are interested in using increasingly smaller grains because ultra-fine grained materials are of higher strength than metals with larger grains.
In the aluminum industry, Field’s work to know whether aluminum is formed along a direction of easy deformation or crosswise so it can allow the industry to more efficiently use the material in its production, minimizing waste and saving money. In the formation of aluminum sheet for making beverage containers, for example, the crystal structure should be as random as possible to maximize the amount of cans made out of a single sheet, he says.
Field has worked with a number of companies in his research, including Advanced Micro Devices, Intel, Boeing, Honeywell, Cabot Performance Materials, Alcoa and Ford Motor Company.