Influence of titanium oxide-based colourants on the morphological and tribomechanical properties of injection-moulded polyoxymethylene spur gears

2019 ◽  
Vol 39 (8) ◽  
pp. 774-783
Author(s):  
Dominik Schubert ◽  
Sebastian Hertle ◽  
Dietmar Drummer
Keyword(s):  
Titanium Oxide ◽  
Mechanical Performance ◽  
Core Material ◽  
Spur Gears ◽  
Delivery Methods ◽  
White Pigment ◽  
Crystalline Core ◽  
Coarse Microstructure ◽  
Tribomechanical Properties ◽  
Carrier Systems

Abstract Regardless of colouration for functional or aesthetic purposes, technical polymer parts, like gears, require consistent properties. However, there is a lack of research into the effect of colourants on the tribomechanical properties of gears. Therefore, the effects of two pigments, titanium dioxide (white) and chrome antimony titanium oxide (yellow), and three delivery methods, masterbatch, liquid colour and direct compounding, on part morphology, dimensions, tribological and mechanical performance of injection-moulded polyoxymethylene (POM) spur gears are investigated in this paper. The white pigment accelerates the crystallisation of POM, causing fine and highly-crystalline morphological structures and smaller dimensions. However, the yellow pigment decelerates crystallisation, resulting in a coarser morphology with highly crystalline core material and bigger parts. Furthermore, the delivery method affects only the tribomechanical properties. Using a masterbatch decreases loads at break and increases deflection at break, since the carrier material acts as an impact modifier and a weak spot. The liquid colour decreases wear due to lubricating properties, whereas the pure pigments increases abrasion, especially in combination with a coarse microstructure. However, the effects of carrier systems and changes in morphology are always superimposed. Considering the performance and tolerance of technical components, colourants have to be carefully selected to ensure beneficial properties.

Mechanical performance of honeycomb sandwich structures built by FDM printing technique

2021 ◽  
pp. 089270572199789
Author(s):  
S Gohar ◽  
G Hussain ◽  
A Ali ◽  
H Ahmad
Keyword(s):  
Fused Deposition Modeling ◽  
Mechanical Performance ◽  
Sandwich Structures ◽  
Weight Ratio ◽  
High Strength ◽  
Core Material ◽  
Interfacial Bond Strength ◽  
Fused Deposition ◽  
Competitive Prices ◽  
Composite Face

Honey Comb Sandwich Structures (HCSS) have numerous applications in aerospace, automobile, and satellite industry because of their properties like high strength to weight ratio, stiffness and impact strength. Fused Deposition Modeling (FDM) is a process which, through its flexibility, simple processing, short manufacturing time, competitive prices and freedom of design, has an ability to enhance the functionality of HCSS. This paper investigates the mechanical behavior (i.e. flexural, edgewise compression and Interfacial bond strength) of FDM-built HCSS. The influence of face/core material was examined by manufacturing four types of specimens namely ABS core with Composite (PLA + 15% carbon fibers) face sheets, ABS core with PLA face sheets, TPU core with composite face sheets and TPU core with PLA face sheets. To measure the effect of face sheets geometry, raster layup was varied at 0°/90° and 45°/−45°. The mechanical characterization revealed that an optimum combination of materials is ABS core with composite face sheets having raster layup of 0°/90°. This study indicates that HCSS with complex lamination schemes and adequate mechanical properties could be manufactured using FDM which may widen the applications of FDM on an industrial scale.

Design of composite lattice materials combined with fabrication approaches

2018 ◽  
Vol 53 (3) ◽  
pp. 393-404 ◽  
Author(s):  
Jun Xu ◽  
Yaobo Wu ◽  
Xiang Gao ◽  
Huaping Wu ◽  
Steven Nutt ◽  
...  
Keyword(s):  
Shear Strength ◽  
Mechanical Performance ◽  
Analytical Models ◽  
Core Material ◽  
Foam Core ◽  
Hierarchical Lattice ◽  
Bottom Up ◽  
Lattice Materials ◽  
Assembly Technique ◽  
Composite Lattice

Lattice materials can be designed through their microstructure while concurrently considering fabrication feasibility. Here, we propose two types of composite lattice materials with enhanced resistance to buckling: (a) hollow lattice materials fabricated by a newly developed bottom-up assembly technique and the previously developed thermal expansion molding technique and (b) hierarchical lattice materials with foam core sandwich trusses fabricated by interlocking assembly process. The mechanical performance of sandwich structures featuring the two types of lattice cores was tested and analyzed theoretically. For hollow lattice core material, samples from two different fabrication processes were compared and both failed by nodal rupture or debonding. In contrast, hierarchical lattice structures failed by shear buckling without interfacial failure in the sandwich struts. Calculations using established analytical models indicated that the shear strength of hollow lattice cores could be optimized by judicious selection of the thickness of patterned plates. Likewise, the shear strength of hierarchical foam core truss cores could be maximized (with minimal weight) through design of truss geometry. The bottom-up assembly technique could provide a feasible way for mass production of lattice cores, but the design about how to assembly is critical. Hierarchical lattice cores with foam sandwich trusses should be a suitable choice for future lightweight material application.

scholarly journals Moisture Absorption Effects on the Mechanical Properties of Sandwich Biocomposites with Cork Core and Flax/PLA Face Sheets

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7295
Author(s):  
Hom Nath Dhakal ◽  
Chulin Jiang ◽  
Moumita Sit ◽  
Zhongyi Zhang ◽  
Moussa Khalfallah ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Failure Modes ◽  
Moisture Absorption ◽  
Mechanical Performance ◽  
Core Sample ◽  
Environmental Benefits ◽  
Matrix Cracking ◽  
Core Material ◽  
Poly Lactic Acid ◽  
The Core

The aim of this study was to evaluate the moisture absorption behaviour and its influence on the mechanical properties of newly developed sandwich biocomposites with flax fibre-reinforced poly-lactic acid (PLA) face sheets and soft cork as the core material. Three different types of sandwich biocomposite laminates comprised of different layup configurations, namely, non-woven flax/PLA (Sample A), non-woven flax/PLA and cork as core (Sample B) and non-woven flax/paper backing/PLA, cork as core (Sample C), were fabricated. In order to evaluate the influence of moisture ingress on the mechanical properties, the biocomposites were immersed in seawater for a period of 1200 h. The biocomposites (both dry and water immersed) were then subjected to tensile, flexural and low-velocity falling weight impact tests. It was observed from the experimental results that the moisture uptake significantly influenced the mechanical properties of the biocomposites. The presence of the cork and paper in sample C made it more susceptible to water absorption, reaching a value of 34.33%. The presence of cork in the core also has a considerable effect on the mechanical, as well as energy dissipation, behaviours. The results of sample A exhibited improved mechanical performance in both dry and wet conditions compared to samples B and C. Sample A exhibits 32.6% more tensile strength and 81.4% more flexural strength in dry conditions than that in sample C. The scanning electron microscopy (SEM) and X-ray micro-CT images revealed that the failure modes observed are a combination of matrix cracking, core crushing and face core debonding. The results from this study suggest that flax/PLA sandwich biocomposites can be used in various lightweight applications with improved environmental benefits.

scholarly journals Mechanical Performance of Honeycomb Sandwich Structures Using Three-Point Bend Test

2019 ◽  
Vol 9 (2) ◽  
pp. 3955-3958
Author(s):  
T. Subhani
Keyword(s):  
Mechanical Performance ◽  
Sandwich Structures ◽  
Bend Test ◽  
Core Material ◽  
Honeycomb Core ◽  
Adhesive Film ◽  
Honeycomb Sandwich ◽  
Point Bend Test ◽  
Three Point Bend Test ◽  
Point Bend

In this study, honeycomb sandwich structures were prepared and tested. Facesheets of sandwich structures were manufactured by carbon fiber epoxy matrix composites while Nomex® honeycomb was used as core material. An epoxy-based adhesive film was used to bond the composite facesheets with honeycomb core. Four different curing temperatures ranging from 100oC to 130oC were applied with curing times of 2h and 3h. Three-point bend test was performed to investigate the mechanical performance of honeycomb sandwich structures and thus optimize the curing parameters. It was revealed that the combination of a temperature of 110oC along with a curing time of 2h offered the optimum mechanical performance together with low damage in honeycomb core and facesheets.

Bioactive Organic-Inorganic Hybrids Prepared from Poly(Vinyl Alcohol) via Modification with Metal Oxides and Calcium Salt

2006 ◽  
Vol 309-311 ◽  
pp. 1153-1156 ◽  
Author(s):  
Caihong You ◽  
Toshiki Miyazaki ◽  
Eiichi Ishida ◽  
Masahiro Ashizuka ◽  
Chikara Ohtsuki
Keyword(s):  
Metal Oxides ◽  
Titanium Oxide ◽  
Vinyl Alcohol ◽  
Calcium Salt ◽  
Mechanical Performance ◽  
Bone Substitutes ◽  
Poly Vinyl Alcohol ◽  
Apatite Formation ◽  
Apatite Deposition

Organic polymers with ability of apatite formation in body environment are expected as novel bone substitutes having not only bone-bonding ability, i.e. bioactivity, but also mechanical performance analogous to natural bone. Several metal oxides have been found to be effective for the apatite deposition in body environment. In addition, release of calcium ions from the materials significantly enhances it. In this study, we attempted to synthesize bioactive organic-inorganic hybrids from poly(vinyl alcohol) (PVA) by incorporation of titanium oxide or zirconium oxide as well as calcium salt. Ability of apatite formation on the hybrids was examined in vitro using simulated body fluid (SBF, Kokubo solution). Apatite deposition was observed to occur on the surfaces of PVA/titanium oxide hybrids in SBF, when their compositions were appropriately controlled.

An Experimental Analysis of Bending Behavior of Sandwich Constructions for Transport Industry

2016 ◽  
Vol 827 ◽  
pp. 61-64
Author(s):  
Ladislav Fojtl ◽  
Soňa Rusnáková ◽  
Milan Žaludek ◽  
Vladimír Rusnák
Keyword(s):  
Experimental Analysis ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Core Material ◽  
The Core ◽  
Transport Industry ◽  
Bending Behavior ◽  
The Impact ◽  
Environmental Temperatures ◽  
Sandwich Constructions

In this work the mechanical performance of various sandwich constructions with respect to core material were experimentally evaluated. Sandwich structures were made of glass prepreg and three types of plastic core using vacuum bagging, technology traditionally used for production of parts for transport industry. The aim of this study is to analyze the impact of the core material type and its thickness on bending behavior at different environmental temperatures. Moreover, the effect of core layers compared to one layer core of same thickness was determined. Conducted research provided useful information of bending behavior and showed specific failure modes of individual sandwich constructions.

scholarly journals Investigating the influence of the core material on the mechanical performance of a nitinol wire wrapped helical auxetic yarn

2021 ◽  
pp. 030932472110270
Author(s):  
Nadimul Haque Faisal ◽  
Andrew Fowlie ◽  
Joe Connell ◽  
Sean Mackenzie ◽  
Ryan Noble ◽  
...  
Keyword(s):  
Analytical Model ◽  
Mechanical Performance ◽  
Poisson Ratio ◽  
Axial Strain ◽  
Impact Resistance ◽  
Tensile Tests ◽  
Core Material ◽  
The Core ◽  
Nitinol Wire ◽  
Theoretical Predictions

Helical Auxetic Yarns (HAYs) can be used in a variety of applications from healthcare to blast and impact resistance. This work focuses on the effect of the use of different core materials (e.g. rubber, polyurethane, polytetrafluoroethylene/teflon, polypropylene, polyetheretherketone, polycarbonate, acetal) with a nitinol wire wrap component on the maximum Negative Poisson Ratio (NPR) produced and thus the auxetic performance of Helical Auxetic Yarns (HAYs). From the analytical model, it was found that an acetal core produced the largest NPR when compared to the other six materials. The trend obtained from the experimental tensile tests (validation) correlated closely with the theoretical predictions of the NPR as axial strain was increased. The experimental method presented a maximum NPR at an average axial strain of 0.148 which was close to the strain of 0.155 predicted by theory. However, the maximum experimental NPR was significantly lower than that predicted by the analytical model.

Mechanical Performance of a New Coir Fiber Laminated Composites

2011 ◽  
Vol 217-218 ◽  
pp. 852-855 ◽  
Author(s):  
Jia Yao ◽  
Ying Cheng Hu ◽  
Wei Lu ◽  
Jin Li
Keyword(s):  
Mechanical Performance ◽  
Laminated Composites ◽  
Performance Testing ◽  
Sem Analysis ◽  
Core Material ◽  
Coir Fiber ◽  
Excellent Performance ◽  
Fiber Density ◽  
The Core ◽  
New Type

In order to overcome the uneven distribution of coir fiber density in the materials and the poor forming of the outer surface, a new type of coir fiber hybrid laminated composites has been developed. The non-woven needle felts of coir fiber are added as the core material, wood veneers are as the surface material, and E-type glass fiber felts are as the reinforcement material, the preparation of hybrid laminated composites has been carried out. Through the performance testing and scanning electron microscopy (SEM) analysis, a new type of biomass composite with excellent performance has been successfully developed. The application of coir fiber to obtain good impact toughness of composites has been effectively verified.

Mechanical and Microstructural Characterisation of Dissimilar Friction Stir Welded AA2024-T3 and AA7075-T6 Aluminium Alloys

2010 ◽  
Vol 638-642 ◽  
pp. 1221-1226 ◽  
Author(s):  
A.A.M. da Silva ◽  
E. Aldanondo ◽  
P. Alvarez ◽  
A. Lizarralde ◽  
A. Echeverria
Keyword(s):  
Aluminium Alloys ◽  
Mechanical Performance ◽  
Base Material ◽  
Fusion Welding ◽  
Friction Stir ◽  
Base Materials ◽  
Coarse Microstructure ◽  
Microstructural Characterisation ◽  
Mechanical And Microstructural Properties ◽  
Welding Processes

Friction Stir Welding (FSW) is a solid-state joining process whereby no bulk melting of the base material occurs during joining. FSW avoids severe distortion and formation of as-cast coarse microstructure as well as defects arising from melting and solidification during traditional fusion welding processes. The objective of this investigation is to evaluate the effect of joining parameters on the mechanical and microstructural properties of dissimilar aluminium alloys (3 mm thick AA2024-T3 and AA7075-T6 sheets) joints produced by FSW. Microstructural features have been analysed; while mechanical performance has been investigated in terms of hardness and tensile testing. In both welding configurations the boundary between the base materials at the stir zone is clearly delineated, i.e., no material mixing is observed.

Effect of salt water exposure on foam-cored polyurethane sandwich composites

2018 ◽  
Vol 22 (4) ◽  
pp. 1256-1273 ◽  
Author(s):  
Z Huo ◽  
M Mohamed ◽  
JR Nicholas ◽  
S Anandan ◽  
K Chandrashekhara
Keyword(s):  
Moisture Absorption ◽  
Mechanical Performance ◽  
Salt Water ◽  
Flexural Modulus ◽  
Interfacial Fracture ◽  
Core Material ◽  
Foam Core ◽  
Sandwich Composites ◽  
Water Exposure ◽  
Polyurethane Composite

This study investigated the effect of moisture absorption on the mechanical performance of polyurethane sandwich composites. The core material was a closed cell polyurethane foam. Face sheets were made of E-glass/polyurethane composite laminates. Vacuum-assisted resin transfer molding process was used to manufacture specimens for testing. The foam core, laminates, and sandwich composites were submerged in salt water for prolonged periods of time. Mechanical property degradation due to moisture absorption for each constituent was evaluated. Compression test was performed on the foam core samples. Laminates were evaluated by three-point bending tests. The interfacial bond strength in the sandwich structure was evaluated by double cantilever beam mode-I interfacial fracture test. The testing results revealed that the effect of salt water exposure on the compressive properties of the foam core is insignificant. The flexural modulus of polyurethane laminates degraded 8.9% and flexural strength degraded 13.0% after 166 days in 50% salinity salt water at 34°C conditioning. The interfacial fracture toughness of polyurethane sandwich composites degraded 22.4% after 166 days in 50% salinity salt water at 34°C conditioning.

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