Generation of microscopic libraries. Design and fabrication of “diffusion multiples”.
Several blocks of Ti and Ti alloys with beta-stabilizing elements (Cr,Mo,V) were placed in a pure Ti capsule. The ensemble was subjected to a hot isostatic pressing (HIP) process and to long-term heat treatments in order to improve contact between the surfaces of the different blocks and to promote diffusion bonding between them. Thus a wide range of quaternary and quinary alloys with gradient compositions were formed (see figure on the right), which will be tested in order to determine the combination of elements that yields the best mechanical performance. Diffusion multiples are proving extremely useful to fast-screen multielement alloys with very limited material waste.
Generation of macroscopic libraries. Additive alloy melting.
A high throughput casting system that allows fabricating bulk samples (cylinders with several centimetres in diameter) has been set-up (see figure on the left). This methodology is being utilized to optimize the composition of steels and Co alloys for components that must operate under extreme temperatures.
Virtual design of composites using a multiscale approach.
Multiscale modeling tools capable of predicting the mechanical behavior of advanced polymer-based composites from their constituent properties and architecture are being put in place. As a first step, the mechanical behavior of the matrix (epoxy 8552) and several fibers (Kevlar KM2), e-glass, and carbon AS4, as well as their interfaces, are being tested. The figure below illustrates the push-in test utilized to measure the resistance of matrix-fiber interfaces.