This study explores the production, characterization, and performance evaluation of carbon fiberreinforced
polymer (CFRP) composite filaments designed for fused deposition modeling (FDM)
applications. The primary objective was to investigate the influence of milled carbon fiber (MCF)
content on the mechanical, moisture absorption, and morphological properties of polypropylene
(PP)-based composites. Composite filaments were produced by blending micro-sized MCFs with PP
granules, followed by a two-step extrusion process to create filaments with varyingMCFcontents
(1–24 wt%). Test specimens were fabricated using 3D printing to evaluate the performance of the
composite materials. The results demonstrated a significant enhancement in mechanical properties
compared to neat PP. The composite with 9.09 achieved optimal performance, exhibiting
increases in tensile and flexural strengths by 74% and 99%, respectively, relative to neat PP. However,
higherMCFcontents (16 and 24 wt%) led to reduced mechanical properties due to insufficient fiber-matrix
adhesion, resulting in fiber pull-out. Moisture absorption studies revealed that the inclusion of
MCFs increased the water uptake of the composites, with higher fiber concentrations correlating to
greater moisture absorption. These findings underline the potential of MCF-reinforced PP composites
for applications requiring improved mechanical performance, such as lightweight structural
components. The study identifies an optimal fiber content of 9.09 wt% for maximizing strength while
minimizing moisture-related trade-offs. Future efforts could focus on enhancing fiber-matrix
bonding to improve performance at higher fiber concentrations.
 

Cavitation damage, evolution, and features with time are serious problems confronting designers and users of high-speed hydraulic machines. The stepwise erosion technique clarifies the evolution of cavitation damage and its features over time. The technique involves exposing a test sample to repeated very low durations of erosion, followed by accurate relocation in the SEM. This allows fora detailed study of the actual wear processes within a material, providing a solid foundation for understanding material failure. The experiments were conducted using an ultrasonic vibratory horn functioning at 19.5 kHz frequency and 50 µm ± 0.2 um peak-to-peak amplitude. The tested material was cold-rolled austenitic stainless steel SUS 304 (18 Cr-8 Ni). The results show that the slip bands formed due to shock waves’ impact are the preferential sites for early material removals. Material removal starts gradually along the slip bands that form at the grain boundary and then progresses into the grain. The results also showed that the microjets formed pits that were a few micrometers in size and separated from one another. These pits have remained the same shape and size over time, confirming their limited role in the evolution of cavitation damage. The initiation and progression of inherent cracks resulting from plastic deformation, as well as the characteristics of dislodged particles, strongly support the conclusion that shockwave impacts cause fatigue failure as the mechanism of cavitation erosion.

Potential uses for electromagnetic launchers in defense systems, space exploration, and transportation have recently emerged. In addition, this accelerator has many applications, such as deploying small satellites into low-earth orbit and accelerating high-speed trains (e.g., bullet trains and Hyperloop) with a low-cost propulsion system instead of expensive linear motors, particularly in space applications. Therefore, the full capability and optimization of these launchers’ efficiency are still required. Therefore, this paper focuses on presenting a new design to decrease the coil’s magnetic circuit reluctance and boost the magnetic flux lines by adding a laminated iron yoke surrounding the coil. This design makes the inductance value of the iron-yoked accelerator twice the inductance in case of the absence of the iron-yoke at its peak. Additionally, the initial inductance of the iron-yoked accelerator is approximately 65 …