scholarly journals Manufacturing, Heat Treatment and Investigation of Foam-Filled Tubes

2021 ◽  
Vol 4 (2) ◽  
pp. 93-96
Author(s):  
Domonkos Balázs Kincses ◽  
Alexandra Kemény ◽  
Borbála Leveles ◽  
Dóra Károly
Keyword(s):  
Heat Treatment ◽  
Metal Foam ◽  
Mechanical Energy ◽  
Syntactic Foam ◽  
Metal Foams ◽  
Ex Situ ◽  
Compression Tests ◽  
Pressure Infiltration ◽  
Specific Strength ◽  
Heat Treated

Abstract Composite metal foams are hybrid structures with the main advantages of high specific strength and mechanical energy absorption associated with low density. In the course of our research, we successfully manufactured functional metal foams of EN AC-44200 matrix filled with lightweight expanded clay aggregate particles (LECAPs) in EN AW-6060 alloy tubes with a diameter of 50 mm and a wall thickness of 5 mm. Manufacturing was performed by low-pressure infiltration directly into the aluminium tube. Six different types of samples were examined: metal matrix syntactic foam, in-situ metal foam, ex-situ metal foam, and their heat-treated pairs. In the compression tests, the heat treatment provided a visible improvement in the results of the ex-situ metal foams.

scholarly journals Effect of Heat Treatment on the Compressive Behavior of Zinc Alloy ZA27 Syntactic Foam

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 792 ◽  
Author(s):  
Nima Movahedi ◽  
Graeme Murch ◽  
Irina Belova ◽  
Thomas Fiedler
Keyword(s):  
Heat Treatment ◽  
Microstructural Analysis ◽  
Syntactic Foam ◽  
Metallic Matrix ◽  
Ductile Deformation ◽  
Zinc Alloy ◽  
Syntactic Foams ◽  
Compression Tests ◽  
Static Compression ◽  
Heat Treated

Zinc alloy (ZA27) syntactic foams (SF) were manufactured using expanded perlite (EP) particles and counter-gravity infiltration casting. Due to a variation of the metallic matrix content, the density of the produced foam samples varied from 1.78 to 2.03 g·cm−3. As-cast and solution heat-treated samples were tested to investigate the compressive properties of the ZA27 syntactic foam. To this end, quasi-static compression tests were conducted. In addition, microstructural analysis of the as-cast and heat-treated syntactic foams was carried out using scanning electron microscopy. The results indicate that the heat treatment alters the microstructure of the ZA27 alloy matrix from a multiphase dendrite to a spheroidized microstructure with improved ductility. Moreover, the heat treatment considerably enhances the energy absorption and plateau stress ( σ pl ) of the syntactic foam. Optical analysis of the syntactic foams under compression shows that the dominant deformation mechanism of the as-cast foams is brittle fracture. In comparison, the heat-treated samples undergo a more ductile deformation.

The Fracture Properties of Sandwich Structures Based on a Metal Foam Core

2014 ◽  
Vol 936 ◽  
pp. 2054-2062
Author(s):  
Yiou Shen ◽  
Yan Li ◽  
Wesley Cantwell ◽  
Yu Yuan Zhao
Keyword(s):  
Metal Foam ◽  
Sandwich Structures ◽  
Compaction Pressure ◽  
Metal Foams ◽  
Compression Tests ◽  
Fracture Properties ◽  
Indentation Tests ◽  
Point Bend ◽  
Average Size ◽  
Two Parameters

The fracture properties of a series of metal foam sandwich structures based on glass fiber-reinforced polyamide 6,6 composite (GF/PA6,6) skins have been investigated. The open cell core materials were manufactured using the Lost Carbonate Sintering (LCS) process, a recently-developed technique for manufacturing metal foams. Initially, the effect of varying the compaction pressure used in producing the metal foams as well as the density of the samples were investigated through a series of compression tests. Here, it was shown that the compressive strength and the elastic modulus of the foams varied with density and compaction pressure, in spite of the fact that the average size of the cells in these foams were insensitive to either of these two parameters. The resistance of sandwich structures to localized loading was investigated through a series of indentation tests. Here, it was shown that the indentation response of sandwich structures could be characterized using a simple indentation law, the parameters of which did not exhibit any clear dependency on the density of the foam. Finally, three point bend tests on the sandwich structures have shown that their loading-bearing properties were sensitive to foam density.

Surface Modification of Diamonds in Diamond/Al-Matrix Composite

2008 ◽  
Vol 59 ◽  
pp. 125-130 ◽  
Author(s):  
C. Edtmaier ◽  
Ludger Weber ◽  
Reza Tavangar
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Treatment Temperature ◽  
Pressure Infiltration ◽  
Argon Gas ◽  
Diamond Particles ◽  
Heat Treated ◽  
Modified Surface ◽  
Al Matrix Composite ◽  
Al Matrix

Fe- or Mn-powders were mixed with the diamonds and the mixtures were heat treated under different gas atmospheres like hydrogen or argon gas and at varying temperatures in order to roughen the surface of the diamond particles. Subsequently the reaction layers are removed by the addition of aqueous solutions of HCl. The modified surface structure after the etching process is investigated by electron microscopy showing increased roughening of the formerly flat faces of the diamond particles with increasing heat treatment temperature. After drying the diamonds, composites were prepared by gas pressure infiltration with pure Al. For treatments in the temperature range from 750 to 850°C the thermal conductivity can be improved by up to 20 percent compared to composites based on un-treated powders.

scholarly journals Characterisation of Hybrid Metal Matrix Syntactic Foams

2015 ◽  
Vol 812 ◽  
pp. 219-225 ◽  
Author(s):  
Imre Norbert Orbulov ◽  
Kornél Májlinger
Keyword(s):  
Volume Fraction ◽  
Mechanical Energy ◽  
Matrix Material ◽  
Hollow Spheres ◽  
Base Material ◽  
Outer Diameter ◽  
Syntactic Foams ◽  
Compression Tests ◽  
Pressure Infiltration ◽  
Geometrical Properties

High quality aluminium matrix syntactic foams (AMSFs) were produced by pressure infiltration. This method can ensure the maximal volume fraction of the reinforcing hollow spheres and very low amount of unwanted or matrix porosities. By this method hybrid MMSFs with mixed metal and ceramic hollow spheres were also produced. The matrix material was AlSi12 alloy and two different types – produced by Hollomet GmbH in Germany – of hollow spheres were used: Globomet (GM) and Globocer (GC). The geometrical properties of the hollow spheres were similar (average outer diameter), but their base material was pure iron and Al2O3+SiO2 in the case of GM and GC hollow spheres respectively. The volume fraction of the reinforcing hollow spheres were maintained at ~65 vol%, but the ratio of them was altered in 20% steps (100% GM + 0% GC, 80% GM + 20% GC...). The results of the compression tests showed, that the compressive strength, yield strength, plateau strength, structural stiffness and the absorbed mechanical energy values increased with higher ceramic hollow sphere reinforcement ratio. The fracture strains of the investigated MMSFs decreased with the higher GC ratio. Generally the strength values also increased with higher diameter to height (H/D) ratio from H/D=1 to H/D=1.5 and 2.

scholarly journals Additive Effects of Postharvest Calcium and Heat Treatment on Reducing Decay and Maintaining Quality in Apples

1994 ◽  
Vol 119 (1) ◽  
pp. 49-53 ◽  
Author(s):  
William S. Conway ◽  
Carl E. Sams ◽  
Chien Yi Wang ◽  
Judith A. Abbott
Keyword(s):  
Heat Treatment ◽  
Cell Wall ◽  
Calcium Chloride ◽  
Compression Test ◽  
Additive Effects ◽  
Pressure Infiltration ◽  
Chloride Solutions ◽  
Heat Treated ◽  
Golden Delicious

`Golden Delicious' apples (Malus domestics Borkh.) were treated with heat or CaCl2 solutions or a combination thereof to determine the effects of these treatments on decay and quality of fruit in storage. Heat treatment at 38C for 4 days, pressure infiltration with 2% or 4% solutions of CaCl2, or a combination of both, with heat following CaCl2 treatment affected decay and firmness during 6 months of storage at 0C. The heat treatment alone reduced decay caused by Botrytis cinerea (Pers.:Fr.) by ≈30%, while heat in combination with a 2% CaC12 solution reduced decay by ≈60 %. Calcium chloride solutions of 2% or 4% alone reduced decay by 40 % and 60 %, respectively. Heat treatments, either alone or in combination with CaC12 treatments, maintained firmness (80 N) best, followed by fruit infiltrated with 2% or 4% solutions of CaCl2 alone (70 N) and the nontreated controls (66 N). Instron Magness-Taylor and Instron compression test curves show that heat-treated fruit differed qualitatively and quantitatively from nonheated fruit. Heat treatment did not increase the amount of infiltrated Ca bound to the cell wall significantly, and a combination of heat treatment after CaCl2 infiltration increased surface injury over those fruit heated or infiltrated with CaCl2 solutions alone.

scholarly journals Effect of Strain Hardening on Precipitation Kinetics in ATI 718Plus

2017 ◽  
Vol 907 ◽  
pp. 167-172
Author(s):  
Bilal Hassan ◽  
Yann Jansen ◽  
Sebastien Nouveau ◽  
Jonathan Corney
Keyword(s):  
Heat Treatment ◽  
Grain Boundaries ◽  
Strain Hardening ◽  
Inconel 718 ◽  
Important Process ◽  
Compression Tests ◽  
Precipitation Kinetics ◽  
Phase Precipitation ◽  
Heat Treated ◽  
Δ Phase

ATI 718Plus components are manufactured by forging a wrought billet in stages to obtain the desired geometry and microstructure. Parts are then heat treated to optimized proportions of γ’ and η phases. η phase is a plate-like phase that precipitates on the grain boundaries of ATI 718Plus, similar to δ phase in Inconel 718. However, the complete kinetic behaviour of η phase precipitation during forging and heat treatment is still not fully understood. This paper investigates the effects of strain hardening on η phase precipitation kinetics in ATI 718Plus. This is achieved through the use of isothermal hot compression tests and heat treatment. Strain hardening was found to affect the η precipitation kinetics considerably. The results reported are a contribution to a fuller understanding of this important process

Effect of Laser Forming on the Energy Absorbing Behavior of Metal Foams

2021 ◽  
Author(s):  
Tom Zhang ◽  
Yubin Liu ◽  
Y. Lawrence Yao
Keyword(s):  
Metal Foam ◽  
Metal Foams ◽  
Laser Forming ◽  
Test Scheme ◽  
Compression Tests ◽  
Forming Process ◽  
Band Formation ◽  
Static Compression ◽  
Energy Absorbing ◽  
The Impact

Abstract Metal foam is light in weight and exhibits an excellent impact absorbing capability. Laser forming has emerged as a promising process in shaping metal foam plates into desired geometry. While the feasibility and shaping mechanism has been studied, the effect of the laser forming process on the mechanical properties and the energy absorbing behavior in particular of the formed foam parts has not been well understood. This study comparatively investigated such effect on as-received and laser formed closed-cell aluminum alloy foam. In quasi-static compression tests, attention was paid to the changes in the elastic region. Imperfections near the laser irradiated surface were closely examined and used to help elucidate the similarities and differences in as-received and laser formed specimens. Similarly, from the impact tests, the dynamically induced deformation and crush band formation were investigated with a modified Charpy impact test scheme. Differences in specific energy absorption were studied and were related to the defects formed during laser forming process. The relative density distribution and evolution of foam specimens were numerically investigated. Laser induced imperfections lead to very minor decrease in the energy absorbing ability of the metal foam, and laser forming still remain as a viable shaping process for metal foams.

scholarly journals Phase Transitions in the α–γ–β Spodumene Thermodynamic System and Impact of γ-Spodumene on the Efficiency of Lithium Extraction by Acid Leaching

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 519
Author(s):  
Colin Dessemond ◽  
Gervais Soucy ◽  
Jean-Philippe Harvey ◽  
Philippe Ouzilleau
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Extraction Efficiency ◽  
Mechanical Energy ◽  
Acid Leaching ◽  
Thermodynamic System ◽  
Coarse Fraction ◽  
X Ray ◽  
Heat Treated ◽  
Lower Heat

Heat-treatment of spodumene concentrate at 1323 K (1050 °C) for 30 min in a rotary kiln yielded a successful decrepitation. Particle size decreased from 2 cm to less than 425 µm for 80% of the initial mass. X-ray analysis of both fractions did not reveal the presence of α-spodumene or γ-spodumene. The coarse fraction was ground to less than 425 µm with minimal mechanical energy and mixed with the finer fraction to perform lithium extraction. The lithium extraction efficiency reached 98 wt% without the need for flotation. Some aspects of the thermodynamic behavior of the spodumene system were assessed. Results show that metastable γ-spodumene may hinder the formation of β-spodumene at lower heat treatment temperatures. Some heat-treated samples presented non-negligible γ-spodumene content and lithium extraction efficiency decreases as the γ content increases. Finally, the assumed irreversibility of the transformations was studied by analyzing heat-treated samples following long controlled-storage periods. The results show that concentrate composition is not static over the studied time. This suggests that the β formation is not as irreversible as claimed. It is recommended to avoid long periods between heat-treatment and extraction to avoid the slow conversion of β-spodumene to other allotropes, which are less susceptible to lithium extraction.

Tensile and Creep Behavior of Ordered Orthorhombic Ti2A1Nb-Based Alloys

1990 ◽  
Vol 213 ◽  
Author(s):  
R.G. Rowe ◽  
D.G. Konitzer ◽  
A.P. Woodfield ◽  
J.C. Chesnutt
Keyword(s):  
Heat Treatment ◽  
Titanium Aluminide ◽  
Room Temperature ◽  
Single Phase ◽  
Two Phase ◽  
Creep Properties ◽  
Specific Strength ◽  
Heat Treated ◽  
Titanium Aluminide Alloys

ABSTRACTTitanium aluminide alloys with compositions near Ti-25A1-25Nb at.% were prepared by both rapid solidification and ingot techniques. Their tensile and creep properties were studied after heat treatment to produce various microstructures containing ordered orthorhombic (O) [1], ordered beta (βo), and α2 phases. It was found that these alloys had higher specific strength from room temperature to 760°C than conventional α2 alloys. Ductility and tensile strength of O+βo alloys were strongly dependent upon heat treatment, with the highest strength observed as-heat-treated, and the highest ductility after long term aging. The creep resistance of single phase O and two phase O+βo alloys was strongly dependent upon heat treatment.

scholarly journals Syntactic Iron Foams’ Properties Tailored by Means of Case Hardening via Carburizing or Carbonitriding

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4358
Author(s):  
Jörg Weise ◽  
Dirk Lehmhus ◽  
Jaqueline Sandfuchs ◽  
Matthias Steinbacher ◽  
Rainer Fechte-Heinen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Hardening ◽  
Metal Foam ◽  
Mechanical Performance ◽  
Syntactic Foam ◽  
Metal Foams ◽  
Metal Injection Molding ◽  
Case Hardening ◽  
Two Phase ◽  
Gear Wheels

Metal foam inserts are known for their high potential for weight and vibration reduction in composite gear wheels. However, most metal foams do not meet the strength requirements mandatory for the transfer of sufficiently high levels of torque by the gears. Syntactic iron and steel foams offer higher strength levels than conventional two-phase metal foams, thus making them optimum candidates for such inserts. The present study investigates to what extent surface hardening treatments commonly applied to gear wheels can improve the mechanical properties of iron-based syntactic foams. Experiments performed thus focus on case hardening treatments based on carburizing and carbonitriding, with subsequent quenching and tempering to achieve surface hardening effects. Production of samples relied on the powder metallurgical metal injection molding (MIM) process. Syntactic iron foams containing 10 wt.% of S60HS hollow glass microspheres were compared to reference materials without such filler. Following heat treatments, the samples’ microstructure was evaluated metallographically; mechanical properties were determined via hardness measurements on reference samples and 4-point bending tests, on both reference and syntactic foam materials. The data obtained show that case hardening can indeed improve the mechanical performance of syntactic iron foams by inducing the formation of a hardened surface layer. Moreover, the investigation indicates that the respective thermo-chemical treatments can be applied to composite gear wheels in exactly the same way as to monolithic ones. In the surface region modified by the treatment, martensitic microstructures were observed, and as consequence, the bending limits of syntactic foam samples were increased by a factor of three.

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