In This Issue
Competitive Materials and Solutions
December 1, 1998 Volume 28 Issue 4
The Bridge, Volume 28, Number 4 - Winter 1998

Engineering Competitive Materials (editorial)

Tuesday, December 1, 1998

Author: James C. Williams

Today's marketplace for manufactured goods is customer driven. Increasingly sophisticated consumers demand low-cost, highly specialized products, tailored to meet specific needs. These manufactured products derive their competitive value from several sources, including appropriate designs and materials.

As product-development and design-cycle times become shorter and the willingness to engineer improvements after a product is introduced lessens, the maturity of materials technology is becoming a key determinant of commercial success. Typically, ensuring maturity requires either extensive production and testing of new materials or testing of components made from them to verify the reproducibility of material properties and processing capability. This is a time-consuming and expensive approach, one that is no longer consistent with the current environment of rapid product design and reduced time to market.

Fortunately, the field of materials and materials processing is evolving from one dominated by enlightened empiricism to one increasingly dependent on sophisticated computational and analytical tools. By incorporating first principles and knowledge derived from experience, these tools can accurately interpolate the behavior of materials within the experience domain for a known application. Currently, however, these tools do not do a very good job of predicting the performance of materials for applications where no experience exists.

The result is that the development of new materials or new methods of processing them often does not keep pace with design innovations. This is a critical shortcoming. Effective new-product realization requires that design and materials availability move forward in parallel.

Computational-based tools that model production processes and simulate operating environments are helping to improve this linkage. The use of statistical methods to identify key variables during processing and in service is gaining acceptance. The ability to characterize materials using an arsenal of virtual diffraction and spectroscopy-based techniques, for instance, has created a better understanding of the effects of processing and material composition on performance, before materials are actually created in large quantity and tested.

The type and number of products that benefit from improved materials and materials processes is so large that it is impractical and unnecessary to enumerate them here. Two of the papers in this issue of The Bridge, from the October technical symposium at the 1998 National Academy of Engineering Annual Meeting, illustrate the vital role that new materials play in two exciting and challenging technology areas, semiconductors and fusion energy.

The starting point in the discovery process for a new material is defining the composition of matter that becomes the basis for the material. Today, improved computational methods allow interatomic bonding and molecular structure to be described ab initio. When coupled with new experimental techniques such as combinatorial chemistry, a myriad of possibilities can be explored with the computer and then efficiently refined in the laboratory. This allows the rapid convergence of many compositional options to a new material with the desired physical properties.

For most successful new materials applications, knowing the correct set of physical properties is necessary but not sufficient. We also need to understand the effect that processing has on the properties and behavior of the final material. Simulation and knowledge-based modeling are becoming more helpful in this regard, but there is much more to be done in this area.

The final phase of discovery involves comparing the physical and mechanical properties of a new material with the requirements imposed by the operating environment of the intended application. In the case of biomaterials, for example, the human body represents a complex and variable environment, whereas the operating environment for semiconducting materials can be more rigorously defined. In materials used in autos, aircraft, gas turbines, and other load-bearing applications, the response of a material to loading, temperature, oxidizing or corrosive elements, and other factors must be analyzed and understood.

To summarize, computational and analytic tools are playing an increasingly important role in the creation of next-generation materials. However, much more work needs to be done to fully integrate these tools into the product-development process. Bringing to maturity a new material in the same timeframe as a new design is essential if materials and materials processing technology are to remain full partners in the realization of competitive products. This represents an exciting challenge and a huge opportunity.

About the Author:James C. Williams, a member of the National Academy of Engineering, is general manager, engineering materials technology laboratories, GE Aircraft Engines. He chaired the NAE steering committee that organized the technical symposium, Materials - The Opportunity, held 6 October during the 1998 NAE Annual Meeting.