Fabrication of Aluminium Foam Components by Using Powder Compact Melting Method

Volume 3 ◽

10.1115/esda2004-58607 ◽

2004 ◽

Cited By ~ 2

Author(s):

S. Guarino ◽

V. Tagliaferri

Keyword(s):

Powder Compact ◽

Experimental Tests ◽

Aluminium Foam ◽

Metal Powders ◽

Characterization Methods ◽

Melting Method ◽

Precursor Material ◽

Inadequate Knowledge ◽

Manufacturing Techniques ◽

Energy Absorbing

Recently, closed cell cellular metals have been gaining a very high interest due to their unique characteristic applications in various technology domains. They combine the advantages of a metal with the structural advantages of foam. Among these, aluminium foams have created a great interest due to their light weight structure and their various applications in the automotive, aerospace and allied industries. Aluminium foam possesses high stiffness and low density, it has good energy-absorbing properties making it good for crash-protection and packaging and it has attractive heat-transfer properties that permit to use these materials to cool electronic equipment and as heat exchangers in engines. However, its manufacturing techniques and characterization methods need more attention. The inadequate knowledge on the physical phenomena governing the foaming process does not allow to obtain products with repeatable characteristics. In this paper aluminium foams in various fabrication components were produced by applying the powder compact melting method. In particular metal powders (AlSi7) and powdered gas-releasing blowing agents (TiH2) were mixed and subsequently pressed to obtain a foamable precursor material. The resulting precursor was then foamed by heating it up to above its melting point. Experimental tests were performed to study the fabrication of aluminum foam components and with the extent of optimize the pressing parameters of the foamable precursor material, the foaming temperature and the heating rate during foaming. It was studied the effects of geometrical discontinuities in the mould (such as holes, restrictions, etc) on the evolution and on the morphology of metal foams.

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FOAMING AGENT FOR ALLOYS OF ALUMINIUM FOAMS

Scientific Bulletin Series D : Mining, Mineral Processing, Non-Ferrous Metallurgy, Geology and Environmental Engineering ◽

10.37193/sbsd.2018.2.06 ◽

2018 ◽

Vol 32 (2) ◽

pp. 53-59

Author(s):

Jozsef Juhasz ◽

Vasile Hotea ◽

Keyword(s):

Thermal Analysis ◽

Pore Structure ◽

Powder Compact ◽

Matrix Alloy ◽

Aluminium Foam ◽

Foaming Agent ◽

Melting Technique ◽

Foam Production

The powder compact melting technique for aluminium foam production as practised today accepts a certain mismatch between foaming agent decomposition and matrix alloy melting temperatures.This mismatch is believed to influence the pore structure in an unfavourable way. Adjustment of TiH 2 decomposition as well as liquidus and solidus temperatures of matrix alloys can be used to counteract it. Effects of TiH 2 thermal are investigated using thermal analysis. TiH 2 variants gained via annealing treatments were used to produce aluminium foam precursor materials.

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Recent Progress in Manufacturing Techniques of Printed and Flexible Sensors: A Review

Biosensors ◽

10.3390/bios10120199 ◽

2020 ◽

Vol 10 (12) ◽

pp. 199

Author(s):

Dinesh Maddipatla ◽

Binu B. Narakathu ◽

Massood Atashbar

Keyword(s):

Recent Progress ◽

Research Work ◽

Materials Characterization ◽

Characterization Methods ◽

Flexible Sensors ◽

Significant Research ◽

Printed Sensors ◽

Manufacturing Techniques ◽

Work Done

This review provides an outlook on some of the significant research work done on printed and flexible sensors. Printed sensors fabricated on flexible platforms such as paper, plastic and textiles have been implemented for wearable applications in the biomedical, defense, food, and environmental industries. This review discusses the materials, characterization methods, and fabrication methods implemented for the development of the printed and flexible sensors. The applications, challenges faced and future opportunities for the printed and flexible sensors are also presented in this review.

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An exploration of binder jetting of copper

Rapid Prototyping Journal ◽

10.1108/rpj-12-2014-0180 ◽

2015 ◽

Vol 21 (2) ◽

pp. 177-185 ◽

Cited By ~ 85

Author(s):

Yun Bai ◽

Christopher B Williams

Keyword(s):

Maximum Temperature ◽

Powder Size ◽

Metal Powders ◽

Content Type ◽

Material Development ◽

Powder Packing ◽

Structural Electronics ◽

Manufacturing Techniques ◽

Future Work ◽

Binder Jetting

Purpose – The purpose of this paper is to explore the use of binder jetting to fabricate high-purity copper parts. The ability to fabricate geometrically complex copper shapes would have implications on the design and manufacture of components for thermal management systems and structural electronics. Design/methodology/approach – To explore the feasibility of processing copper via binder jetting, the authors followed an established material development process that encompasses powder selection and tuning process parameters in printing and thermal cycles. Specifically, the authors varied powder size and sintering cycles to explore their effects on densification. Findings – Three differently sized copper powders were successfully printed, followed by sintering in a reducing atmosphere. It was found that a 15-μm-diameter powder with a sintering cycle featuring a 1,080°C maximum temperature provides the most dense (85 per cent) and pure (97 per cent) final copper parts of the parameters tested. Research limitations/implications – Due to powder-based additive manufacturing techniques’ inherent limitations in powder packing and particle size diameter, there are difficulties in creating fully dense copper parts. To improve thermal, electrical and mechanical properties, future work will focus on improving densification. Originality/value – The paper demonstrates the first use of binder jetting to fabricate copper artifacts. The resulting copper parts are denser than what is typically found in binder jetting of metal powders (without infiltration); significant opportunity remains to further optimize the manufacturing process by introducing novel techniques to tailor the material properties for thermal/electrical applications.

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Design and Analysis of Bicycle Helmet with Impaxx Foam Liner

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.706-708.1778 ◽

2013 ◽

Vol 706-708 ◽

pp. 1778-1781

Author(s):

Tso Liang Teng ◽

Cho Chung Liang ◽

Chien Jong Shih ◽

Van Hai Nguyen

Keyword(s):

Heat Dissipation ◽

Low Cost ◽

Experimental Tests ◽

Absorption Test ◽

Bicycle Helmet ◽

Shock Absorption ◽

Liner Material ◽

Bicycle Helmets ◽

And Performance ◽

Energy Absorbing

Currently, expended polystyrene (EPS) are widely used as liner material in bicycle helmet. Due to its characteristics is excellent performance, lightweight, low cost of manufacturing. However, EPS has some disadvantage as difficulty to optimize energy absorbing in different areas of head and inferior effect of heat dissipation and a brittle characteristic. This study focuses on to find a replacement material for EPS foam to improve liner of bicycle helmet. Impaxx energy absorbing (EA) foams present strong potential in overcoming such problems of EPS foam. To make certain that all bicycle helmets reach efficiency, the helmets are required to pass shock absorption test of EN1078 standard. This study performs finite element analyses of helmet impact tests using LS-DYNA software. Simulation results indicate Impaxx foams are suitable for shock absorption test according to the EN1078 standard. Therefore these results encouraged the authors to extend the manufacturing work to cover the creating helmet design and performance experimental tests.

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New characterization methods for monitoring small resonant frequency variation: Experimental tests in the case of hydrogen detection with uncoated silicon microcantilever-based sensors

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2014.03.098 ◽

2014 ◽

Vol 199 ◽

pp. 269-276 ◽

Cited By ~ 10

Author(s):

M.T. Boudjiet ◽

J. Bertrand ◽

C. Pellet ◽

I. Dufour

Keyword(s):

Resonant Frequency ◽

Experimental Tests ◽

Frequency Variation ◽

Hydrogen Detection ◽

Characterization Methods

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Preparation of Intercalated Organic Montmorillonite DOPO-MMT by Melting Method and Its Effect on Flame Retardancy to Epoxy Resin

Polymers ◽

10.3390/polym13203496 ◽

2021 ◽

Vol 13 (20) ◽

pp. 3496

Author(s):

Junming Geng ◽

Jianyu Qin ◽

Jiyu He

Keyword(s):

Electron Microscopy ◽

Flame Retardant ◽

Epoxy Resin ◽

Flame Retardancy ◽

Flame Retardants ◽

Characterization Methods ◽

Melting Method ◽

Organic Montmorillonite ◽

Ul 94 ◽

Flame Retardant Properties

An intercalated organic montmorillonite DOPO-MMT was prepared through the melting method using 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as a modifier. Epoxy resin (EP) composites were prepared with DOPO-MMT, DOPO, MMT, and the physical mixtures of DOPO+MMT as flame retardants. The microstructure of the flame retardants and EP samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The flame retardant properties, thermal stability, and residual char structure of the EPs were studied by the limited oxygen index (LOI) test, the UL-94 vertical burning test, thermogravimetric analysis (TGA), the differential scanning calorimeter (DSC) test, the cone calorimeter (CONE) test as well as other characterization methods. The results showed that the intercalated organic montmorillonite DOPO-MMT can be successfully prepared by the melting method and that the MMT is evenly dispersed in the EP/DOPO-MMT composite in the form of nanosheets. The EP/DOPO-MMT nanocomposites showed the optimal flame retardancy (LOI, UL-94, PHRR, etc.) among the EPs with DOPO, MMT, and the physical mixture of DOPO+MMT. The flame-retardant grade of the material reached V-0.

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Insight Into the Design of Blast-Mitigating Floor Mats Using Design of Experiments

Volume 13: Safety Engineering, Risk, and Reliability Analysis ◽

10.1115/imece2019-10598 ◽

2019 ◽

Author(s):

Hisham Kamel

Keyword(s):

Design Of Experiments ◽

Computational Study ◽

Close Contact ◽

Dynamic Performance ◽

Experimental Tests ◽

Element Model ◽

Influential Factor ◽

Fe Model ◽

Energy Absorbing ◽

Insight Into

Abstract Recently, Improvised explosive devices (IEDs) have evolved into a major and significant threat inflicting substantial human casualties and property damage. The majority of injuries are to the lower extremities since they are in close contact to vehicle floor. Floor mats have been developed to mitigate the effects of IEDs blasts. This paper reports a computational study on the energy absorbing behavior of a novel commercial floor mat — Skydex — for foot protection. The design of experiments (DOE) approach was applied to investigate the effect of shape variations on the dynamic performance of a finite element model of Skydex. The FE model was verified using experimental tests on samples produced using 3D printing technique. The DOE approach revealed significant insight into the design of Skydex. It confirmed that shape variables have strong effect on the amount of energy absorbed and the transmitted load. DOE specifically identified the radius of the mid-section of Skydex as the most influential factor in controlling the mode of deformation under compression. In addition, it uncovered the interaction effect between the radius of curvatures of the two hemispheres and upper and lower radii. Finally, DOE revealed the bi-trade-off relations between energy absorbed, transmitted load and mass. These were shown in meaningful and helpful plots which will help the development of Skydex design.

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Fatigue Cracking of Additively Manufactured Materials—Process and Material Perspectives

Applied Sciences ◽

10.3390/app10165556 ◽

2020 ◽

Vol 10 (16) ◽

pp. 5556

Author(s):

Torsten Fischer ◽

Bernd Kuhn ◽

Detlef Rieck ◽

Axel Schulz ◽

Ralf Trieglaff ◽

...

Keyword(s):

Additive Manufacturing ◽

Fatigue Strength ◽

Process Control ◽

High Performance ◽

Chemical Engineering ◽

Fatigue Cracking ◽

Metal Powders ◽

Wide Range ◽

Manufacturing Techniques ◽

The Impact

Strong efforts are made internationally to optimize the process control of laser additive manufacturing processes. For this purpose, advanced detectors and monitoring software are being developed to control the quality of production. However, commercial suppliers of metal powders and part manufacturers are essentially focused on well-established materials. This article demonstrates the potential of optimized process control. Furthermore, we outline the development of a new high temperature structural steel, tailored to best utilize the advantages of additive manufacturing techniques. In this context, the impact of production-induced porosity on fatigue strength of austenitic 316L is presented. Additionally, we discuss the first conceptual results of a novel ferritic steel, named HiperFer (High Performance Ferrite), which was designed for increased fatigue strength. This ferritic, Laves phase-strengthened, stainless steel could be used for a wide range of structural components in power and (petro)chemical engineering at maximum temperatures ranging from about 580 to 650 °C. This material benefits from in situ heat treatment and counteracts process-related defects by “reactive” crack obstruction mechanisms, hampering both crack initiation and crack propagation. In this way, increased fatigue resistance and safety can be achieved.

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Inclusion of Tapered Tubes in Enhancing the Crash Performance of Automotive Frontal Structures

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.553.1 ◽

2013 ◽

Vol 553 ◽

pp. 1-6

Author(s):

Zaini Ahmad ◽

Greg Nagel ◽

David Thambiratnam

Keyword(s):

Experimental Tests ◽

Element Model ◽

Oblique Impact ◽

Absorption Capacity ◽

Design Guidelines ◽

Similar System ◽

Energy Absorbing ◽

Guidelines And Recommendations ◽

Frontal Collisions ◽

Dynamic Impact Loading

This paper treats the design and analysis of an energy absorbing system. Experimental tests were conducted on a prototype, and these tests were used to validate a finite element model of the system. The model was then used to analyze the response of the system under dynamic impact loading. The response was compared with that of a similar system consisting of straight circular tubes, empty and foam-filled conical tubes. Three types of such supplementary devices were included in the energy absorbing system to examine the crush behavior and energy absorption capacity when subjected to axial and oblique impact loadings. The findings were used to develop design guidelines and recommendations for the implementation of tapered tubes in energy absorbing systems. To this end, the system was conceptual in form such that it could be adopted for a variety of applications. Nevertheless, for convenience, the approach in this study is to treat the system as a demonstrator car bumper system used to absorb impact energy during minor frontal collisions.

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