Force and Microstructure Variation of SLM Prepared AlMgSc Samples during Three-Point Bending

Lightweight parts manufactured by metal selective laser melting (SLM) are widely applied in machinery industries because of their high specific strength, good energy absorption effect, and complex shape that are difficult to form by mechanical machining. These samples often serve in three-dimensional stress states. However, previous publications mainly focused on the unidirectional tensile/compressive properties of the samples. In this paper, AlMgSc samples with different geometric parameters were prepared by the SLM process, and the variation of force and microstructure during three-point bending were systematically investigated. The results demonstrate that the deformation resistance of these samples has good continuity without mutation in bending, even for brittle materials; the bending force-displacement curves exhibit representative variation stages during the entire bending process; the equivalent bending strength deduced from free bending formula is not applicable when compactability is less than 67%. The variations of grain orientation and size of the three representative bending layers also show regularity.

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Investigation of selected parameters effect on 3D printed sand mold properties through Taguchi method

Rapid Prototyping Journal ◽

10.1108/rpj-11-2019-0294 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Guili Gao ◽

Weikun Zhang ◽

Zhimin Du ◽

Qingyi Liu ◽

Yanqing Su ◽

...

Keyword(s):

Layer Thickness ◽

Process Parameters ◽

Bending Strength ◽

Three Dimensional ◽

Sand Mold ◽

Optimal Process ◽

Content Type ◽

Three Point Bending ◽

Boundary Properties ◽

3D Printed

Purpose The major concern technologies during the processing through three-dimensional printing (3DP) are the mechanical and boundary properties of sand models. The parameters such as activator content, resolution X, layer thickness and re-coater speed play a vital role in 3DP sand components. The purpose of this paper is to recommend the optimal process parameters for the best sand mold properties. Design/methodology/approach In this paper, taking the parameters of the activator content, resolution X, layer thickness and re-coater speed as the influence factors, an orthogonal test of L16(44) was designed to discuss the influences of those parameters on the mechanical and boundary properties. Three-point bending (3PB) test was used to characterize the actual bending strength, and the boundary accuracy was assessed by the deviation of the three-point bending samples compared with its design scale. Findings The experimental results showed that the resolution X and layer thickness are the main parameters affecting sand mold properties. The strength will attain its maximum when the resolution X and layer thickness are the minimum. The optimal parameters were screened and verified by the confirmation test. The optimal process parameters for best strength and less gas evolution are the activator of 0.19%, resolution X of 0.1 mm, layer thickness of 0.28 mm and re-coater speed of 210 mm/s. Originality/value The novelty of this paper is the select of significant parameters on 3D-printed sand model properties. A mathematical model was built to analyze the effect of these parameters. The optimal process parameters for the best properties were got.

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Collagen-Calcium Phosphate Hybrids for Bone Grafts: A Novel Route Leading to High Initial Strengths

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.309-311.1185 ◽

2006 ◽

Vol 309-311 ◽

pp. 1185-1190 ◽

Cited By ~ 3

Author(s):

Xu Dong Li ◽

Xiao Min Wang ◽

Xiao Yan Lin ◽

Jian Ming Jiang ◽

Xing Dong Zhang

Keyword(s):

Calcium Phosphate ◽

Bending Strength ◽

Three Dimensional ◽

Bone Grafts ◽

X Ray Diffraction ◽

Three Point Bending ◽

Dimensional Network ◽

Efficient Route ◽

Mechanical Strengths

An organic/inorganic composite hydrogel route was used to prepare collagen-calcium phosphate hybrids with high mechanical strengths, via in-situ mineral synthesis during collagen fibrillogenesis followed by dehydration. An array of characterization techniques including X-ray diffraction and Fourier transform infrared spectroscopy analyses confirmed that the final products are analogous to natural bone. A three-point bending strength of 70 MPa, much higher than the values reported in the literature, was recorded in the present case, due to the three dimensional network structure achieved between inorganic and organic phases. This innovative method provides an efficient route to produce bone grafts with the desirable mechanical properties which are dependent upon the actual inorganic/organic ratio and water content.

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Bending Strength of Sandwich Beams with Nanocomposites Core

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.577 ◽

2009 ◽

Vol 79-82 ◽

pp. 577-580 ◽

Cited By ~ 1

Author(s):

Meng Kao Yeh ◽

Chia Min Lin

Keyword(s):

Bending Strength ◽

Musical Instrument ◽

Bending Test ◽

Core Material ◽

Sandwich Beams ◽

Three Point Bending ◽

Specific Strength ◽

The Face ◽

Multi Walled Carbon Nanotubes ◽

Walled Carbon Nanotubes

Composite materials, having advantages of high specific strength, high specific stiffness, are used in many applications, such as musical instrument, acoustical tile, fire wall, sports equipment, aerospace and vehicle industries. Composite products in the form of sandwich structures are specifically useful in recent years. In this paper, the bending strength of sandwich structure made by graphite/epoxy face laminates and core material made by multi-walled carbon nanotubes (MWNTs) reinforced polymer was investigated experimentally. In experiment, the three-point bending test was performed to measure the bending properties of sandwich beams. The influences of fiber orientation in the face laminates and MWNTs content in polymer reinforced nanocomposite core material on the bending strength of sandwich beams were discussed in this paper. The failure mechanism of sandwich beams with various fiber orientations in the face laminates was also discussed.

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Simulative analysis of the bending property of woven fabric by the comprehensive handle evaluation system for fabrics and yarns

Textile Research Journal ◽

10.1177/0040517516660894 ◽

2016 ◽

Vol 87 (16) ◽

pp. 1977-1990 ◽

Cited By ~ 3

Author(s):

Fengxin Sun ◽

Chaoyu Chen ◽

Sai Liu ◽

Huanhuan Jin ◽

Linge He ◽

...

Keyword(s):

Evaluation System ◽

Woven Fabrics ◽

Woven Fabric ◽

Bending Test ◽

Element Analysis ◽

Textile Materials ◽

Three Point Bending ◽

Bending Property ◽

Bending Process ◽

Force Displacement

The comprehensive handle evaluation system for fabrics and yarns can be used to measure the bending property of fabrics and yarns based on three-point bending, in principle. In order to gain a better understanding of the bending mechanism of woven fabrics under three-point bending and to better interpret the influencing factors in the bending process, weaving-structure models of woven fabrics were built using finite element analysis based on ABAQUS software. Simulated bending force–displacement curves were compared with experimental curves based on the bending characteristic parameters extracted from the curves, and stress distribution on the fabric and the pressing pin were visually displayed during the bending process. The results show that the simulated curves have good agreement with the experimental curves. The effects of the property parameters of materials, including the Poisson’s ratio, friction coefficient and modulus of yarns and the structure phase and thread arrangement density of fabrics, as well as apparatus parameters, including diameters, the interval of the supporting pins and the distance of the jaws, on bending test were investigated. It is expected that the three-point bending method will help better characterize the bending property of textile materials.

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Experimental Study of Manufacture and Mechanical Behavior of Sandwich Structure With Composite Foldcores

Volume 5B: 39th Mechanisms and Robotics Conference ◽

10.1115/detc2015-47022 ◽

2015 ◽

Author(s):

Kaiyu Jiang ◽

Keqian Cai ◽

Minjie Wang ◽

Danyang Zhao ◽

Zhong You

Keyword(s):

Compression Strength ◽

Failure Modes ◽

Three Dimensional ◽

Compression Modulus ◽

Curing Process ◽

Molding Process ◽

Specific Strength ◽

The Core ◽

Load Carrying ◽

Force Displacement

Foldcore Sandwich structures with high specific strength and specific stiffness will be the aeronautic and astronautic main load-carrying structure materials. Curing process temperature of the Carbon and Kevlar prepreg materials were determined by the best curing process extrapolation method. And then, three dimensional foldcore specimens were manufactured by hot-pressing and piecewise curing molding process. In the compression test, compression force-displacement variation laws and deformation failure modes of the foldcores with different thickness were studied by changing the thickness of core wall. Furthermore, the panel constraints on the properties of compression are studied by pasting panel on the bottom of core and both sides of the core. The researches shows: the compression strength and compression modulus was multiplied increased, and the brittle degree of core was increased with the core wall thickness increasing. The panel restriction for foldcore greatly improved the compression modulus and compression strength.

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Effects of hostile solutions on the static and dynamic behavior of carbon/epoxy composites

Journal of Composite Materials ◽

10.1177/00219983211020094 ◽

2021 ◽

pp. 002199832110200

Author(s):

H Ersen Balcıoğlu ◽

Raif Sakin ◽

Halit Gün

Keyword(s):

Bending Strength ◽

Laminated Composites ◽

Fatigue Behavior ◽

Laminated Composite ◽

Test Sample ◽

Solution Concentration ◽

Static Stability ◽

Three Point Bending ◽

Sem Image ◽

Solution Type

Fiber-reinforced laminated composite is often used in harsh environments that may affect their static stability and long-term durability as well as residual strength. In this study, the effect of heavy chemical environments such as acid and alkaline and retaining time for these environments on flexural strength and flexural fatigue behavior of carbon/epoxy laminated composites were investigated. In this context, carbon/epoxy was retained into an acidic and alkaline solution having 5%, 15%, and 25% concentration by weight for 1–4 months. Fatigue behavior of carbon/epoxy was determined under dynamic flexural load, which corresponds to 80%, 70%, 60%, 50%, and 40% of static three-point bending strength of the test sample. SEM image of damaged specimens was taken to describe the failure mechanism of damage which occurs after fatigue. Also, to better understand environmental condition on the fatigue life, results were compared with results of carbon/epoxy laminated composites, which were not retained into any environments (unretained). The test results showed that the solution type, solution concentration, and retaining time caused noticeable changes in the static and dynamic strengths of carbon/epoxy laminated composites.

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Chlorine-Functional Silsesquioxanes (POSS-Cl) as Effective Flame Retardants and Reinforcing Additives for Rigid Polyurethane Foams

Molecules ◽

10.3390/molecules26133979 ◽

2021 ◽

Vol 26 (13) ◽

pp. 3979

Author(s):

Anna Strąkowska ◽

Sylwia Członka ◽

Karolina Miedzińska ◽

Krzysztof Strzelec

Keyword(s):

Flame Retardants ◽

Elevated Temperatures ◽

Bending Strength ◽

Reaction System ◽

Fire Retardant ◽

Polyurethane Foams ◽

Polymerization Reaction ◽

Three Point Bending ◽

One Step

The subject of the research was the production of silsesquioxane modified rigid polyurethane (PUR) foams (POSS-Cl) with chlorine functional groups (chlorobenzyl, chloropropyl, chlorobenzylethyl) characterized by reduced flammability. The foams were prepared in a one-step additive polymerization reaction of isocyanates with polyols, and the POSS modifier was added to the reaction system in an amount of 2 wt.% polyol. The influence of POSS was analyzed by performing a series of tests, such as determination of the kinetics of foam growth, determination of apparent density, and structure analysis. Compressive strength, three-point bending strength, hardness, and shape stability at reduced and elevated temperatures were tested, and the hydrophobicity of the surface was determined. The most important measurement was the determination of the thermal stability (TGA) and the flammability of the modified systems using a cone calorimeter. The obtained results, after comparing with the results for unmodified foam, showed a large influence of POSS modifiers on the functional properties, especially thermal and fire-retardant, of the obtained PUR-POSS-Cl systems.

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Experimental Investigation of Ti-6Al-4V with a Biaxial Tensile Test Setup at Elevated Temperature

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.622-623.273 ◽

2014 ◽

Vol 622-623 ◽

pp. 273-278 ◽

Cited By ~ 1

Author(s):

Marion Merklein ◽

Sebastian Suttner ◽

Adam Schaub

Keyword(s):

Elevated Temperature ◽

Elevated Temperatures ◽

Tensile Tests ◽

Advanced Materials ◽

Uniaxial Tensile ◽

Plastic Yielding ◽

Characterization Methods ◽

Specific Strength ◽

Biaxial Tensile ◽

Stress States

The requirement for products to reduce weight while maintaining strength is a major challenge to the development of new advanced materials. Especially in the field of human medicine or aviation and aeronautics new materials are needed to satisfy increasing demands. Therefore the titanium alloy Ti-6Al-4V with its high specific strength and an outstanding corrosion resistance is used for high and reliable performance in sheet metal forming processes as well as in medical applications. Due to a meaningful and accurate numerical process design and to improve the prediction accuracy of the numerical model, advanced material characterization methods are required. To expand the formability and to skillfully use the advantage of Ti-6Al-4V, forming processes are performed at elevated temperatures. Thus the investigation of plastic yielding at different stress states and at an elevated temperature of 400°C is presented in this paper. For this reason biaxial tensile tests with a cruciform shaped specimen are realized at 400°C in addition to uniaxial tensile tests. Moreover the beginning of plastic yielding is analyzed in the first quadrant of the stress space with regard to complex material modeling.

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