The need for new materials, faster time-to-market, and lower costs have made the use of high-throughput experimentation more widespread. One emerging application is the screening and exploring of metallic alloys.
Different alloy compositions can be deposited precisely either simultaneously as a gradient of compositions, or in a rapid serial process as a series of individual spots on a common substrate. This results in a library of alloy compositions and processes for rapid screening.
These libraries can then be screened for basic structural and mechanical properties upon incremental anneals to gain insight into phase stability with temperature, and determine their correlation with mechanical properties. As an example, IMI is demonstrating the viability of Low Density High Entropy Alloys (LDHEAs) as a lightweighting approach for vehicle applications.
Once materials candidates are identified, they are co-sputtered with guns located at different regions, and operating under different conditions, to form gradients of different elements. Gradient films can be rapidly characterized at every point across the film.
Example of composition data richness (EDS) for a 4-element AlCrTiZn alloy generated from one gradient deposition on one coupon.
LDHEAs have the potential to dramatically improve specific yield strength (SYS) with a concomitant improvement in the balance between strength and ductility of metals, along with reduced sensitivity to processing conditions and corrosion. However, the complex and nuanced materials and process phase-space for LDHEAs makes screening and optimizing bulk alloys complicated and much more time-consuming than traditional alloys.
The high-throughput experiment approach has the potential to screen broad compositional regions of complex alloys quickly, significantly accelerating development and optimization of these complex and nuanced alloy materials.