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Morphology-property-relationship of thermo-mechanically graded self-reinforced polypropylene composites
(2015-02-17)
In this paper the relationship between different composite morphologies and their mechanical properties is to be investigated. By manufacturing two different tape-based polypropylene composites in a compression moulding process, four varying degrees of compaction will be generated. The morphological structure is analyzed using confocal laser light microscopy and wet chemically etched specimen cross-sections. The etching process removes the amorphous phase in the polymer, making the macromolecular orientations and ...
Aufsatz
A framework for the computer-aided planning and optimisation of manufacturing processes for components with functional graded properties
(2015-02-17)
In this contribution a framework for the computer-aided planning and optimisation of functional graded components is presented. The framework is divided into three modules - the "Component Description", the "Expert System" for the synthetisation of several process chains and the "Modelling and Process Chain Optimisation". The Component Description module enhances a standard computer-aided design (CAD) model by a voxel-based representation of the graded properties. The Expert System synthesises process steps stored ...
Aufsatz
Comparative investigation of two-dimensional imaging methods and X-ray tomography in the characterization of microstructure
(2017-10-02)
The microstructural features of three different materials have been quantified by means of 2D image analysis and X-ray micro-computer tomography (CT) and the results were compared to determine the reliability of the 2D analysis in the material characterization. The 3D quantification of shrinkage pores and Fe-rich inclusions of an Al-Si-Cu alloy by X-ray tomography was compared with the statistical analysis of the 2D metallographic pictures and a significant difference in the results was found due to the complex ...
Aufsatz
Innovative Materials for Novel Concepts for Internal Heat Exchangers
(2018-07-27)
Internal heat exchangers are often employed in solar thermal applications as well as in many other applications that involve heat, and, for the most part, consist of metallic materials (copper, stainless steel). Corrugated stainless steel tubes are easy to assemble, and are commonly used in various storage geometries. In order to significantly reduce costs, alternative materials, such as plastics, can function as excellent substitutes. Alternative heat exchangers for the following examinations using various materials ...
Aufsatz
The Manufacture of Hot-Compacted Layered Composite Systems Made of Oriented Semifinished PP-Films
(2014-03-04)
Monoaxial stretched PP-films are used for the manufacture of hot-compacted layered composites. These are layered with stretched co-extruded coupling agent films, and are consolidated to laminates by means of a hot-compaction process, which employs pressure and temperature. This paper aims to examine the influence of the process settings on the properties of the composites during the hot-compaction process. For this purpose, the mechanical values will be determined by means of tensile testing variously compacted and ...
Aufsatz
Parameter identification for constitutive models of innovative textile composite materials using digital image correlation
(2019-11-18)
This contribution focuses on an innovative composite material consisting of textile layers made from continuous wooden fibers embedded in a thermoplastic matrix. A finite element simulation of potential use‐cases is planned to support the development process and to study the suitability of the material in an architectural context. The simulation is based on a constitutive model assuming homogenous orthotropic elastic behavior and will be expanded to include multiscale modeling in future research. The material parameters ...
Aufsatz
Climatic Ageing of Components of Polymer Based Electrochromic Devices
(2013-09-09)
Combining a shading function and a polycarbonate window displays an attractive alternative to the currently employed glass roof in vehicles. However, the ageing of such a device must be investigated before any application. Therefore, our investigations focus on the ageing of the components of a polycarbonate based electrochromic device. The optical, electrical, mechanical and electrochemical properties of the ion storage layer as well as the substrate will be assessed after storage in a climate with a high humidity ...
Aufsatz
Characterization of Anisotropic Properties of Hot Compacted Self-Reinforced Composites (SRCs) via Thermal Diffusivity Measurement
(2019-11-01)
The mechanical properties of self-reinforced composites (SRCs) produced in a hot compaction process significantly depend on the process parameters. Only a little deviation of the process temperature or pressure causes the component to act differently under mechanical load. This is a chance and a challenge at the same time, since this process is difficult to handle but by properly controlling the process parameters, the mechanical properties can be adjusted, even locally for one component. In this research SRC are ...
Aufsatz
A Closer Look at the Bonding Capacity of Thick Metal-Plastic Hybrids
(2019-03-01)
Metal-plastic hybrids have a lot of advantages compared to purely metal or purely plastic parts. A good design for metal-plastic hybrids can help to save weight, for example in automotive applications. Therefore, it is important to understand the joining mechanisms between both materials. Aluminum AlSi9Cu3(Fe) and polyamide 6.6 with 35 % glass fibers were used as joining partners. The materials were joined by enclosing the metal part at least partially with plastic right inside the injection molding tool. Afterwards, ...
Aufsatz
UV Pre-Treatment for Polycarbonate for Bonding LSR in a Multi-Component Injection Molding Process
(2019-03-01)
In this study, the influence of UVC radiation and the influence of ozone on the surface energy of specimens made of polycarbonate were investigated. In an additional step, the peeling resistance of silicone flaps, which were overmolded, onto pre-treated PC plates of multicomponent specimens were analyzed. For this purpose, the samples were exposed to UVC radiation for different lengths of time, ranging from 5 s to 3 600 s. To further evaluate the influence of the ozone created by the UVC in the presence of oxygen, ...