This study proposed an effective and sustainable technique for the curing of carbon fiber reinforced polymers (CFRPs) using microwaves. The method involves applying a metallic resonance coating layer to envelop the CFRP composite’s surface. Next, the composite is positioned within a multi-mode cavity, which is used as an applicator, and is powered by four 250 W solid-state power amplifiers. To ensure precise control over the heating pattern and achieve uniform heating of the composite, a sophisticated control algorithm is developed. This algorithm can independently regulate the phase, power level, and frequency of each power amplifier. The experimental results confirm the effectiveness of this proposed approach in achieving precise control over the microwave-based curing process for CFRPs.

We demonstrate an all polarization-maintaining (PM) fiber mode-locked laser seeded, hybrid fiber/solid-slab picosecond pulse laser system which outputs $40~\unicode[STIX]{x03BC}\text{J}$, 10 ps pulses at the central wavelength of 1064  nm. The beam quality factors $M^{2}$ in the unstable and stable directions are 1.35 and 1.31, respectively. $15~\unicode[STIX]{x03BC}\text{J}$ picosecond pulses at the central wavelength of 355 nm are generated through third harmonic generation (THG) by using two $\text{LiB}_{3}\text{O}_{5}$ (LBO) crystals, in order to get better processing efficiency on polycrystalline diamonds. The high pulse energy and beam quality of these ultraviolet (UV) picosecond pulses are confirmed by latter experiments of material processing on polycrystalline diamonds. This scheme which combines the advantages of the all PM fiber mode-locked laser and the solid-slab amplifier enables compact, robust and chirped pulse amplification-free amplification with high power picosecond pulses.

Meso-scale structure in polymeric foams determines the mechanical properties of the material. Density variations, even more than variations in the anisotropic void structure, can greatly vary the compressive and tensile response of the material. With their diverse use as both a structural material and space filler, polyurethane (PU) foams are widely studied. In this manuscript, quantitative measures of the density and anisotropic structure are provided by using micro X-ray computed tomography (microCT) to better understand the results of mechanical testing. MicroCT illustrates the variation in the density, cell morphology, size, shape, and orientation in different regions in blown foam due to the velocity profile near the casting surface. “Interrupted” in situ imaging of the material during compression of these sub-regions indicates the pathways of the structural response to the mechanical load and the changes in cell morphology as a result. It is found that molded PU foam has a 6 mm thick “skin” of higher density and highly eccentric morphological structure that leads to wide variations in mechanical performance depending upon sampling location. This comparison is necessary to understand the mechanical performance of the anisotropic structure.