US Air Force Developing New Tools to Accelerate Composite Certification

A team of researchers from the U.S Air Force Research Laboratory and Cornell High Energy Synchrotron Source (CHESS) are developing the capability to accelerate certification of advanced manufactured composite structures.

The partnership is creating a new materials sub-facility called the Materials Solutions Network which will drive composite manufacturing into a physics-based exact science that can be predicted and modelled allowing faster implementation of low-cost, short-term and limited-life technologies.

It is hoped the new facility will allow breakthroughs in materials, processes and designs for aerospace and military components. The ability to process material models faster than ever will enable shorter times toward certification of new materials and difficult processing methods such as additive manufacturing.

The beamline will allow manufacturers and researchers to observe materials in real-time and at atomic scale for structural components such as the stationary section of a rotary system for DOD technologies or additively manufactured articles for limited life applications.

Obtaining tangible measurement data such as material structure in regards to gaps and interfacial quality is now a reality. Problems and processes can be eliminated sooner and refined for quality control and consistency.

Traditionally, composites manufacturing is mainly done by hand. Hence, the processing is as much art as it is science. Predictive modelling relies on numerous assumptions and experimental data. Reproducibility is low and ever-changing to new and improved material.

This development pushes a real-time, high-resolution understanding of the manufacturing of composites. The research reveals processing effects and variations on thermoplastic and thermoset composites during consolidation processes such as stamping and additive manufacturing.

We are now able to look at the crystallisation of thermoplastic feedstock and composites during 3D printing in real-time, at the one-micrometer resolution.

Dr. Hilmar Koerner, research team lead in the Structural Materials Division of AFRL

Two new X-ray beamlines – a structural materials beamline (for which higher-energy X-rays are required to penetrate, e.g., metals) and a functional materials beamline (with lower energies for polymers and composites) are housed at the facility.

The structural materials beamline uses high energy X-rays to understand the evolving internal structure of metals, ceramics and composites during service and processing conditions.

The functional materials beamline is designed for analysis of soft materials, such as organic molecule and polymer-based materials and composites used in lightweight structural components and organic electronics, during processing and under real-life load conditions.

The X-ray beam at the functional materials beamline is only one-hundredth of the width of a human hair and can probe interfaces between the matrix and the carbon fibre, between layers of printed composites and of bonded structures. Images can be taken at fractions of a second to enhance quality control in revealing behaviour during processing. The beamline allows quick switching between different operating modes, such as small-angle X-ray/wide-angle X-ray scattering, phase contrast imaging and X-ray computed tomography.

Partnerships between the Department of Defense, industry and academia to address DOD challenges in materials discovery, processing and manufacturing of disruptive technologies will enable advances in materials and designs for a multitude of military components.