Pierre Kubelka

Bio: Pierre Kubelka is an academic researcher from Pforzheim University of Applied Sciences. The author has contributed to research in topics: Syntactic foam & Deformation (engineering). The author has an hindex of 2, co-authored 3 publications receiving 4 citations.

Compression Behavior of Low-Pressure Cast AMC Syntactic Foams with High Porosity

Abstract: This work presents a method for the manufacturing of closed-cell aluminum matrix composite syntactic foams (AMCSFs) using a modified and simplified low-pressure infiltration setup. The influence of different wrought and cast alloys on the compressive behavior of these foams was investigated. Through the use of a variety of different cast and wrought alloys, it was possible to determine the Al matrix’ influence on the compressive behavior. The investigated AlX-Al2O3 syntactic foams were manufactured using hollow alumina spheres with AA1050, AA2024, AA5019, AA7075, and A356 Al alloys in the as-cast state. The results of the manufacturing process and the selected process parameters show a good dispersion of the spheres within the AlX matrix with a typical near randomly close-packed structure at the same time. The high-strength Al alloys AA2024 and AA7075 lead to a very brittle deformation behavior of the foams in the compression tests, with a strongly oscillating behavior plateau and relatively low plateau stress level. In contrast, the low- and mid-strength alloys AA1050, AA5019, and A356 show a more ductile behavior with less oscillation at a higher plateau stress level. By the five different combinations of the material partners, it was possible to make a statement about the ductility–strength relation of metallic syntactic foams in dependence on the base matrix.

Influence of Cu, Zn and Si alloying elements on Al alloy foams produced using Mg blowing agent

Abstract: The main focus of the present study is to compare the effect of different alloying elements on Al–Mg alloy foams. Al–Mg15–X10 (X = Cu, Zn and Si) alloy foams were produced via powder metallurgy route by using Mg as a blowing agent. Macro- and microstructural characterisations of the foams were performed using X-ray tomography, X-ray diffraction and scanning electron microscope. Corrosion studies such as weight loss measurement, hydrogen evolution method and potentiodynamic test were conducted. Mechanical properties were evaluated by subjecting the samples to quasi-static compression and microhardness tests. All the alloy foams showed a comparable structure. The Cu-containing foams exhibited the highest strength, while the Zn-containing foams showed the highest expansion. However, the other properties such as brittleness, elastic modulus and burning nature were found to be better for the Si-containing foams.

The influence of infiltration casting technique on properties of metal syntactic foams and their foam-filled tube structures

Abstract: This research provides a comparative study between metal syntactic foams (MSFs) manufactured using two different infiltration casting techniques. Counter-gravity infiltration (CGI) and low-pressure infiltration (LPI) casting methods are employed to manufacture aluminium alloy matrix MSFs with embedded lightweight expanded clay aggregate particles. The cast MSFs from both methods are then used as the core material in the empty aluminium tubes with or without adhesive to produce foam-filled tube (FFT) samples. The MSFs manufactured using the LPI technique show higher density compared to their CGI cast counterparts. The quasi-static compression of the MSFs in axial and lateral loading directions showed the shearing of the MSFs during their deformation. The deformation of the FFTs in axial compression was influenced by the type of adhesive material, while in their lateral compression, the effect of adhesive type was insignificant. The mechanical properties of the MSFs and FFTs using the LPI technique showed higher values. For both casting techniques, the mechanical properties of the MSFs and FFTs in axial compression outperformed their structural values obtained from lateral compression. • Counter gravity infiltration and low-pressure infiltration methods are compared. • The adhesive influences the axial deformation mechanism of the foam-filled tubes. • The differences of the lateral structural values depend on the used casting method.

Low-Cost Light-Weight Composite Metal Foams for Transportation Applications

Abstract: Abstract This paper is dealing with the production and investigation (structural and mechanical) of composite metal foams (CMFs) with AlSi9MgMn matrix and ~60 vol% of different nominal diameter light expanded clay particles (LECPs) filler. The main aim was to produce a cheap CMF grade for automotive industry. The samples were produced by liquid state low pressure infiltration. Cubic samples were manufactured from the produced CMF blocks for structural (optical microscopy, scanning electron microscopy and energy-dispersive x-ray spectrometry (EDS)) and for mechanical (compression) investigations and tests. The CMFs were investigated in as-cast and in T6 heat-treated conditions. The macrostructural investigations showed homogenous structure and sufficient quality infiltration. On the microscopic scale, the EDS investigations revealed a complex interface layer affected by chemical reactions between the matrix material and the filler particles. The compressive test proved the classic foam-like mechanical behavior of the CMFs (with long plateau region). A relationship (valid for both the as-cast and T6 heat-treated conditions) was found between the characteristic properties and the nominal diameter of the filler. Based on these results, the LECPs filled CMFs are ideal candidates for automotive applications with tailorable properties.