Papers by Keyword: Hollow Profile

Abstract: High friction in aluminum hollow profile extrusion limits material flow, process stability, and productivity. Ultrasonic vibration offers a promising approach to reduce friction, yet its application to industrial porthole dies is still insufficiently explored. This study presents the development and investigation of an ultrasonic die sonication system for aluminum extrusion. Finite element extrusion simulations demonstrate that reduced friction leads to lower extrusion forces, decreased profile exit temperatures, and improved material flow. A modified porthole die enabling ultrasonic excitation at multiple positions was designed accordingly. The vibrational behavior of the die was analyzed using three-dimensional modal and harmonic finite element simulations. Suitable excitation frequencies between 18.5 and 23 kHz were identified and experimentally validated by laser vibrometry, confirming effective transmission of ultrasonic vibrations into the die. The simulation results demonstrate the feasibility of ultrasonic die oscillation for aluminum hollow profile extrusion and provide a solid basis for forthcoming extrusion trials and further process optimization. The system was implemented, approved, and is now available for upcoming experimental trials.

Abstract: In order to enhance lightweight potential and fabrication efficiency of structural parts from carbon fiber-reinforced plastics, the approach of locally tailored component properties has proven effective. For braided hollow profiles, however, technical possibilities to achieve process integrated adaption of a components’ mechanical properties are limited. Therefore, a novel braiding process approach for cycle-time-neutral adjustment of a triaxial braids filler yarn count is examined and its advantages for component design are illustrated. The main objective of this study is to evaluate the approaches applicability with regard to process stability and disturbance of product quality. Two consecutive test series are carried out to identify the most influential process variables and to link the variation of these variables with multiple criteria of process quality. A clear dependency between quality and braid angle, braid yarn tension as well as the number of filler yarns the approach is applied on is derived. On that basis a set of process variables for faultless application of the concept is pointed out.

Abstract: The present case study addressed a practical problem of wall thickness attenuation during extrusion to produce a complex thin-walled hollow magnesium profile. A HyperWorks FEM software package was employed to aid in identifying the causes for the wall thickness attenuation. Recommendations were made to adjust the interspacing between the mandrels and the height of the welding chamber. The modified dies yielded much improved results in terms of velocity and hydrostatic pressure uniformity. The wall thickness of the extrudate predicted using FEM simulation was very close to experimental measurements. The case study demonstrated the feasibility of using FEM simulation as a useful tool to solve industrial problems encountered in the production of complex profiles.