Robert Magai

59553374100

Publications - 6

Charpy Impact Test Result Comparison on Reinforcing Materials used in Continuous Filament 3D Printing

Robert Magai Balazs Molnar

Publication Name: Engineering Technology and Applied Science Research

Publication Date: 2025-02-01

Volume: 15

Issue: 1

Page Range: 19354-19357

Description:

With the growing industrial demand for materials that can withstand dynamic loads, composite 3D printing, particularly utilizing continuous fiber reinforcements, presents a promising solution. This study investigates the toughness of three fiber-reinforced materials, namely carbon fiber, Kelvar, and fiberglass, by conducting Charpy impact tests. The results reveal that fiber-reinforced 3D materials significantly outperform standard 3D printed components, with fiberglass showing the highest toughness. These findings demonstrate that fiber-reinforced 3D printed materials offer a viable alternative for applications requiring high toughness and dynamic resistance.

Open Access: Yes

DOI: 10.48084/etasr.8740

Investigation of the Radar Cross-Section and its Optimization Potential for ADAS Tests

Leticia Pekk Robert Magai Norbert Simon Balazs Molnar

Publication Name: Engineering Technology and Applied Science Research

Publication Date: 2025-02-01

Volume: 15

Issue: 1

Page Range: 20493-20499

Description:

The objective of this study is to examine the Radar Cross Section (RCS) of instruments designed for Autonomous Driving Systems (ADAS) testing, with the intention of comparing the results to those of actual human subjects. The RCS values of both dummy and platform objects were documented at varying distances and positions, with the objective of ascertaining the extent to which dummies can serve as substitutes for human values in vehicle radar sensing tests. The findings, substantiated by graphical representations and statistical analyses (e.g., Pearson and Spearman correlation), reveal a moderately strong positive correlation between the RCS and human values, which is statistically significant. The outcomes of the tests demonstrate that the developed instruments can substitute for real human radar cross-section values within the range of 5-15 m. However, as the distance increases, larger deviations are observed. These discrepancies underscore the necessity for a refinement of the dummy design in future ADAS tests, ensuring that distance-sensitive tests accurately reflect real human measurements.

Open Access: Yes

DOI: 10.48084/etasr.9310

Testing the Setup Parameters of 3D Printed Parts Using a 7-axis Measuring Arm

Robert Magai Balazs Molnar

Publication Name: International Journal of Automotive Science and Technology

Publication Date: 2025-12-17

Volume: 9

Issue: 1st Future of Vehicles Conf.

Page Range: 35-40

Description:

Additive manufacturing, particularly Fused Deposition Modeling (FDM), has become a widely adopted technique in prototyping and small-series production. This is primarily due to its high flexibility and cost-effectiveness. However, ensuring dimensional accuracy remains a significant challenge, especially for functional components with tight tolerances. The aim of this study is to investigate the effect of two fundamental FDM parameters, layer height and print speed, on geometric accuracy. Nine configurations were tested by combining three-layer heights (0.1 mm, 0.2 mm, 0.3 mm) with three print speeds (40 mm/s, 60 mm/s, 80 mm/s). The test specimens were printed using an Ultimaker S7 printer with PLA Extrafill filament and subsequently remeasured using a 7-axis Hexagon Absolute Arm coordinate measuring arm. Each part was evaluated at seventeen predefined geometric features, resulting in a total of 153 measurement data points. Deviations were analyzed in comparison with the nominal CAD model values. The results indicate that the combination of 0.2 mm layer height and 60 mm/s print speed (L2S2) yielded the smallest deviations and the most consistent accuracy. Undersizing was typically observed for holes located in the XY-plane, while features along the Z-axis exhibited greater variation. The findings highlight the necessity of coordinated parameter optimization to improve dimensional accuracy.

Open Access: Yes

DOI: 10.30939/ijastech.1753463

The Effect of Heat Treatment on the Mechanical Properties of Continuously Fibre-Reinforced Standardised Specimens

Robert Magai Balazs Molnar

Publication Name: International Journal of Automotive Science and Technology

Publication Date: 2025-12-17

Volume: 9

Issue: 1st Future of Vehicles Conf.

Page Range: 22-27

Description:

This study investigates the influence of post-printing heat treatments on the mechanical characteristics of 3D-printed specimens strengthened with continuous Kevlar filaments. After their fabrication, the specimens underwent thermal annealing at temperatures of 100 °C and 150 °C for either 1 or 3 hours. To assess the effects of these treatments on mechanical performance, tensile tests and microscopic analyses were performed. The findings indicated that the most significant enhancement was observed in specimens annealed at 150 °C for 1 hour, which resulted in an approximately 20% increase in tensile strength compared to untreated samples. Heat treatments at 100 °C for 1 hour and 3 hours led to moderate improvements of 5–8%, whereas extended treatment at 150 °C for 3 hours resulted in a reduction of about 10% in tensile strength. Microscopy revealed that brief, high-temperature treatment enhanced interlayer bonding and decreased internal stress without harming the structure, while prolonged thermal exposure led to local delamination and compromised fibre–matrix adhesion. These results suggest that controlled post-printing heat treatment can enhance the mechanical properties of continuous fibre-reinforced composites, though excessive heat exposure can lead to degradation. Therefore, careful optimisation of temperature and duration is crucial. The outcomes offer valuable insights for improving the structural performance of additively manufactured continuous fibre-reinforced components.

Open Access: Yes

DOI: 10.30939/ijastech.1752437

Testing the Setup Parameters of 3D Printed Parts Using a 7-axis Measuring Arm

Robert Magai Balazs Molnar

Publication Name: International Journal of Automotive Science and Technology

Publication Date: 2025-12-17

Volume: 9

Issue: 1st Future of Vehicles Conf.

Page Range: 35-40

Description:

Additive manufacturing, particularly Fused Deposition Modeling (FDM), has become a widely adopted technique in prototyping and small-series production. This is primarily due to its high flexibility and cost-effectiveness. However, ensuring dimensional accuracy remains a significant challenge, especially for functional components with tight tolerances. The aim of this study is to investigate the effect of two fundamental FDM parameters, layer height and print speed, on geometric accuracy. Nine configurations were tested by combining three-layer heights (0.1 mm, 0.2 mm, 0.3 mm) with three print speeds (40 mm/s, 60 mm/s, 80 mm/s). The test specimens were printed using an Ultimaker S7 printer with PLA Extrafill filament and subsequently remeasured using a 7-axis Hexagon Absolute Arm coordinate measuring arm. Each part was evaluated at seventeen predefined geometric features, resulting in a total of 153 measurement data points. Deviations were analyzed in comparison with the nominal CAD model values. The results indicate that the combination of 0.2 mm layer height and 60 mm/s print speed (L2S2) yielded the smallest deviations and the most consistent accuracy. Undersizing was typically observed for holes located in the XY-plane, while features along the Z-axis exhibited greater variation. The findings highlight the necessity of coordinated parameter optimization to improve dimensional accuracy.

Open Access: Yes

DOI: 10.30939/IJASTECH..1753463

The Effect of Heat Treatment on the Mechanical Properties of Continuously Fibre-Reinforced Standardised Specimens

Robert Magai Balazs Molnar

Publication Name: International Journal of Automotive Science and Technology

Publication Date: 2025-12-17

Volume: 9

Issue: 1st Future of Vehicles Conf.

Page Range: 22-27

Description:

This study investigates the influence of post-printing heat treatments on the mechanical characteristics of 3D-printed specimens strengthened with continuous Kevlar filaments. After their fabrication, the specimens underwent thermal annealing at temperatures of 100 °C and 150 °C for either 1 or 3 hours. To assess the effects of these treatments on mechanical performance, tensile tests and microscopic analyses were performed. The findings indicated that the most significant enhancement was observed in specimens annealed at 150 °C for 1 hour, which resulted in an approximately 20% increase in tensile strength compared to untreated samples. Heat treatments at 100 °C for 1 hour and 3 hours led to moderate improvements of 5–8%, whereas extended treatment at 150 °C for 3 hours resulted in a reduction of about 10% in tensile strength. Microscopy revealed that brief, high-temperature treatment enhanced interlayer bonding and decreased internal stress without harming the structure, while prolonged thermal exposure led to local delamination and compromised fibre–matrix adhesion. These results suggest that controlled post-printing heat treatment can enhance the mechanical properties of continuous fibre-reinforced composites, though excessive heat exposure can lead to degradation. Therefore, careful optimisation of temperature and duration is crucial. The outcomes offer valuable insights for improving the structural performance of additively manufactured continuous fibre-reinforced components.

Open Access: Yes

DOI: 10.30939/IJASTECH..1752437