Characterization Of Mechanical Properties Research Articles

Mechanical property characterizations of woven natural fiber-reinforced polymers 3D printed through a laminated object manufacturing process

ABSTRACT The mechanical properties of woven natural fiber reinforced polymers additively manufactured through Laminated Object Manufacturing (LOM) technology are investigated in this paper. The benefits of both the material and manufacturing process were combined into a sustainable practice, as a potential alternative to traditional synthetic composite materials made from nonrenewable crude oil with limited end-of-life alternatives. Woven jute fiber reinforcements are used to strengthen both synthetic and bio- thermoplastic polymers in creating highly biodegradable composite structures. Such materials, as one of the prospective alternatives for synthetic composites, can be used in many engineering fields such as automobile panels, construction materials, and commodity and recreational products including sports and musical instruments. A LOM 3D printer prototype was designed and built by the authors. All woven jute/polymer biocomposite test specimens made using the built prototype in this study had their mechanical (both tensile and flexural) properties assessed using ASTM test standards and then compared to similar values measured from pure polymer specimens. Improved mechanical characteristics were identified and analyzed. Finally, SEM imaging was performed to identify the polymer infusion and fiber-matrix bonding conditions.

Study on the heat treatment of multispectral ZnS for residual stress reduction

Multispectral ZnS (M − ZnS) will inevitably introduce stresses during the chemical vapor deposition (CVD) polycrystalline growth and hot isostatic pressing (HIPping) stages. In this paper, the generation mechanism and elimination method of residual stresses in M − ZnS are analyzed by means of SEM, transmittance, XRD analysis and mechanical property characterization, and the effects of heat treatment temperature, time and material annealing structure on the apparent morphology, optical and mechanical properties of M − ZnS materials are investigated. The results show that the internal stresses of M − ZnS mainly originate from the CVD ZnS growth and HIPping stages, and the most effective method to reduce the stresses is heat treatment. The key factors affecting the effect of heat treatment include temperature, time, and annealing structure. Selecting a GZ(G) annealing structure combined with a suitable cooling rate for heat treatment of M − ZnS materials will significantly improve the heat treatment effect. More annealing time has a significant effect on the transmittance in the 0.38–3 μm band, and insignificant effect on the transmittance in the 3–5 μm and 8–10 μm bands. Heat treatment will bring some degree of structural changes to the material, often manifested including a trace of hexagonal phase structure, which will affect the optical imaging quality of the window material. Heat treatment contributes to secondary grain growth, with an increase in grain size and a decrease in grain boundaries. Excessive heat treatment accelerates the loss of hardness and bending strength, and also leads to the generation of micro-cracks and macro-cracks in the material, reducing the mechanical properties of the material. Heat treatment holding 200 h and 100 h compared to the unannealed, Vickers hardness decreased by 13.518 and 7.96, respectively, bending strength decreased by 4.77 MPa and 1.73 MPa, respectively. Therefore, in actual production, should not be selected excessive heat treatment time.

Hot-press sintering of SiC whisker reinforced TiB2-B4C composites and its mechanical property characterizations

TiB2-B4C composites modified by SiCW with excellent mechanical properties were prepared using hot-press sintering. The effects of SiCW content on the microstructure, densification behavior and mechanical properties were investigated. The dynamic failure behavior was analyzed through the Hopkinson Bar (SHPB) testing. The results demonstrate that the addition of SiCW can effectively refine the microstructure and simultaneously improve the mechanical properties. The TiB2-B4C composite renforced with 6 wt% SiCW exhibits a nearly full-dense microstructure and excellent mechanical properties. The relative density, flexural strength, Vickers hardness and fracture toughness can reach to 99.95 %, 724 ± 61 MPa, 19.8 ± 0.7 GPa and 6.7 ± 0.3 MPa m1/2, respectively. The dynamic failure behavior exhibits that the damage degree increases with elevated loading speed. Moreover, the single-peak and double-peak of the waveform correspond to the two damage degrees of "broken" and "crushed".

From 2D to 3D electrochemical microfabrication of nickel architectures at room temperature: Synthesis and characterization of microstructure and mechanical properties

Recent development in direct electrochemical 3D microprinting allows the fabrication of 3D metallic micro-components of predominantly noble metals with the positive standard reduction potentials (e.g., Cu, Au, or Pt). These pure metals (e.g., Cu, Au, or Pt) have a small shear modulus up to 60 GPa, which limits one of the important strengthening mechanisms, Taylor hardening. Hence, their mechanical strength is relatively low and limits the application in a structural component. 3D printing of mechanically high-strength metals (e.g., Ni), specifically, printing of microscale parts by direct electrodeposition using a voxel-by-voxel printing technique, is so far very challenging due to the negative standard reduction potential, which leads to hydrogen evolution and unstable printing. In this paper, we demonstrate the stable and successful room temperature (RT) electrochemical printing of Ni micro-architectures by using a newly formulated Ni ink and supporting electrolyte, which were developed through 2D voltammetry and deposition analysis. The micro manufacturing of Ni succeeds at a high deposition speed up to ∼61 nm/s, which is the fastest speed reported so far for microprinting of Ni. 3D printed micropillars feature a heterogeneous nanostructure from ∼13 nm at the center to ∼27 nm at the perimeter. By performing micropillar compression tests, the printed pillars exhibit a high compressive yield-strength of 2.3 ± 0.1 GPa, only ∼15 % lower than 2D processed samples (2.7 ± 0.1 GPa) featuring a homogeneous nanostructure of 27 ± 16 nm. Thus, by deposition of stronger, but less noble metals we show a new pathway to enhance the mechanical robustness of 3D-printed structures, opening up new applications where mechanical rigidity is essential.

Characterization of microstructures and mechanical properties of laser welded TWIP steel plate

In the present study, laser welding of medium-thick TWIP steel plates was studied and the microstructures and mechanical properties of the welded joints obtained at varied welding speeds were characterized. It is shown that a full penetration was achieved in the welded joint, which exhibits a keyhole-shaped configuration. The welded joint displays a single austenitic phase and typical solidification structure composed of cellular, columnar and dendrite grains. With increasing the welding speed, the grains in both the central fusion zone and adjacent heat-affected zone were refined. The latter was attributed to inadequate recrystallization because of decreased heating time at elevated welding speed. The mechanical properties of all welded joints were lower than those of base metal, in which the decline of elongation was more serious than that of strength. This is attributed to the formation of thick columnar crystals and the Al2O3 core-shell structured nanoscale precipitates in the grains of the fusion zone. Moreover, there existed a certain degree of non-uniformity in the microstructures and mechanical properties along the thickness direction of welding seam, and the samples in the upper area of welding seam showed better comprehensive properties than the lower ones. When welded at a moderate speed as 1.0 m/min, the welding seams exhibited the best mechanical properties and the least difference across the thickness direction of the welding seam. This is because the moderate welding speed resulted in the most beneficial macro- and micro-structures as well as grain boundary characteristics.

Characterization and Evaluation of Mechanical Properties of Carbon Nanotube Filler Epoxy Composite

The outstanding mechanical properties of carbon nanotubes (CNT) have made them the focus of extensive investigation. To characterize and study the effects of the different volume fraction of multi walled carbon nanotubes (MWCNTs) on the mechanical properties of the nanocomposites attempted. The purpose of this work is to use experimental techniques to ascertain the mechanical characteristics of the nanocomposite. Tests on mechanical tensile strength were conducted to see how the MWCNT filler content affected the reinforced epoxy nanocomposite. The result of altered percentage of MWCNTs on the mechanical properties of the composites had been inspected. Results showed that 0.2 wt% MWCNT addition has the best effect on the mechanical properties of the matrix.

Characterization of Physical and Mechanical Properties of Tungsten Alloy Surfaces for Electroplasticity-Assisted Dry Cutting Machining

Characterization of Physical and Mechanical Properties of Tungsten Alloy Surfaces for Electroplasticity-Assisted Dry Cutting Machining

Characterization of structural and mechanical properties of HfNbTaTiZr refractory high entropy alloy after gas nitriding

This study was initiated to improve surface hardness and wear resistance of a HfNbTaTiZr refractory high entropy alloy (RHEA) by gas nitriding at a medium temperature (600 °C) for 3 h. Structural characterizations conducted by X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS) equipped scanning electron microscope (SEM) revealed that nitriding led to formation of a 1.5 μm thick surface layer containing precipitates of oxides and nitrides of the alloying elements. Detection of oxides within the surface layer was attributed to the presence residual oxygen in the nitriding atmosphere. Nevertheless, the employed gas nitriding provided remarkably higher scratch resistance compared to the untreated state, as the results of increment in the surface hardness and development of larger compressive residual stress.

Microstructure and Mechanical Properties of Carbon Fiber Phenolic MatrixComposites containing Carbon Nanotubes and Silicon Carbide

A novel class of hybrid composites was prepared containing carbon fibers along with carbon nanotubes and silicon carbide particles in phenolic resin for improved mechanical performance. The loading of carbon fibers was ~60 wt% while carbon nanotubes and silicon carbide particles were reinforced in the fractions of 0.1 wt% and 5 wt%, respectively. Individually reinforced composites containing 0.1 wt% carbon nanotubes and 5 wt% silicon carbide particles were also manufactured for comparison with hybrid composites. Microstructural and mechanical property characterization was performed using electron microscopy and mechanical testing, respectively. Uniform dispersion of nanometer-scale carbon nanotubes and micrometer-scale silicon carbide particles was observed under microscopy. The pooled effect of carbon nanotubes and silicon carbide particles significantly increased the tensile, compressive, and flexural performance of composites while carbon nanotubes offered greater weight fraction value improvement than silicon carbide particles.

Cryogenic rolling impacts on microstructures and properties of a novel Ni–W–Co–Ta medium-heavy alloy

A high-strength Ni–W–Co–Ta medium-heavy alloy (MHA) was prepared through the melting–casting–forging followed by cryogenic rolling process. Detailed microstructure and mechanical property characterizations were conducted to unveil the influence of cyrorolling on Ni–W–Co–Ta MHA. The results revealed that initial equiaxial grains were elongated along the rolling direction firstly and then transformed to fibrous texture with increase in accumulated deformation, in which a large number of slip bands were generated to coordinate the intensive plastic deformation. A sharp increase in dislocation density significantly promoted the dislocation interactions, which, in turn, refined the grains down to nanometer scale. The strength and hardness increased significantly with the increase of the deformation, whereas the elongation decreased sharply. The fracture morphology changed from a typical ductile mode for the undeformed sample gradually to quasi-cleavage and ductile mixed mode for 90% deformed material.

Microscopic and Mechanical Properties Characterization of Laser Beam Welded 5754 to 6063 Aluminum Alloys

Microscopic and Mechanical Properties Characterization of Laser Beam Welded 5754 to 6063 Aluminum Alloys

Experimental research on mechanical, material, and metallurgical properties of Inconel 600: Application in elevated temperature environment

Experimental research on mechanical, material, and metallurgical properties of Inconel 600: Application in elevated temperature environment

A biotechnological approach to upgrade wheat straw into high-performance binderless boards

Wheat straw represents a highly promising source for the production of bio-based materials due to its fibrous composition, naturally optimized structure, and high availability as an agricultural by-product. The present study reports the conversion of wheat straw into high-performing fibreboards without the use of bonding agents. In a first step, straw was converted into fibres using a mild semi chemical pulping process. Subsequently, microbial aqueous retting of the fibres was performed for different periods. The fibres obtained were characterized and the microorganisms involved in the retting process were isolated and sequenced. Quantification of xylanase activity indicated substantial enzymatic hydrolysis of hemicellulose. This biotreatment improved both the drainability of the straw fibres and the mechanical properties of hot-pressed binderless fibreboards. Characterization of mechanical and physical properties revealed impressive flexural strengths of 64 MPa, flexural moduli of 6.8 GPa and internal bond of 1.1 MPa after 8 days of bio treatment. The results exceeded the standard requirements for hardboards and demonstrate the possibility of enhancing the performance of straw based binderless boards with natural biotreatment.

Mechanical Properties Characterization of Glass/Carbon Fiber Hybrid Multilayer Composite under Environmental Aging Condition

Metallic components in boating industry are being replaced with carbon fiber composites due to their light weight, excellent mechanical properties, and corrosion resistance. However, the carbon fiber cost has obstructed the substitution. Hybridization is suggested to merge carbon and glass fibers in cost-effective composites while maintaining the desired engineering properties. This study experimentally examines the impact of hybridization and seawater aging on the mechanical properties of glass and carbon fibers hybrid composites. A range of composites ([C]6, [CGC]s, [C]3[G]3, [GCG]s, and [G]6) are fabricated and aged in simulated seawater solution before their tensile, flexural, impact, and hardness properties are examined. The results revealed degradation in properties due to the ageing, the degree of degradation is influenced by the s hybridization configuration. The [G]6 sample shows the highest tensile strength reduction of 30% compared to 20% for the [C]6. The remaining samples exhibit reduction percentages falling between these two extremes. A similar behavior is observed in the flexural test, though the extremes values are smaller, 10.2%, and 12.5%. The impact and hardness tests showed an inverse relationship between the glass fiber content and impact strength degradation due to aging, while they exhibited a linear correlation for hardness degradation due to ageing.

Characterization of Microstructural and Mechanical Properties of 17-4 PH Stainless Steel by Cold Rolled and Machining vs. DMLS Additive Manufacturing

The 17-4 PH stainless steel is widely used in the aerospace, petrochemical, chemical, food, and general metallurgical industries. The present study was conducted to analyze the mechanical properties of two types of 17-4 PH stainless steel—commercial cold-rolled and direct metal laser sintering (DMLS) manufactured. This study employed linear and nonlinear tensile FEM simulations, combined with various materials characterization techniques such as tensile testing and nanoindentation. Moreover, microstructural analysis was performed using metallographic techniques, optical microscopy, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The results on the microstructure for 17-4 PH DMLS stainless steel reveal the layers of melting due to the laser process characterized by complex directional columnar structures parallel to the DMLS build direction. The mechanical properties obtained from the simple tension test decreased by 17% for the elastic modulus, 7.8% for the yield strength, and 7% for the ultimate strength for 17-4 PH DMLS compared with rolled 17-4 PH stainless steel. The FEM simulation using the experimental tension test data revealed that the 17-4 PH DMLS stainless steel experienced a decrease in the yield strength of ~8% and in the ultimate strength of ~11%. A reduction of the yield strength of the material was obtained as the grain size increased.

Shear Bond Strength to Enamel, Mechanical Properties and Cellular Studies of Fiber-Reinforced Composites Modified by Depositing SiO2 Nanofilms on Quartz Fibers via Atomic Layer Deposition.

Poor interfacial bonding between the fibers and resin matrix in fiber-reinforced composites (FRCs) is a significant drawback of the composites. To enhance the mechanical properties of FRC, fibers were modified by depositing SiO2 nanofilms via the atomic layer deposition (ALD) technique. This study aims to evaluate the effect of ALD treatment of the fibers on the mechanical properties of the FRCs. The quartz fibers were modified by depositing different cycles (50, 100, 200, and 400) of SiO2 nanofilms via the ALD technique and FRCs were proposed from the modified fibers. The morphologies, surface characterizations of nanofilms, mechanical properties, and cytocompatibility of FRCs were systematically investigated. Moreover, the shear bond strength (SBS) of FRCs to human enamel was also evaluated. The SEM and SE results showed that the ALD-deposited SiO2 nanofilms have good conformality and homogeneity. According to the results of FTIR and TGA, SiO2 nanofilms and quartz fiber surfaces had good chemical combinations. Three-point bending tests with FRCs showed that the deposited SiO2 nanofilms effectively improved FRCs' strength and Group D underwent 100 deposition cycles and had the highest flexural strength before and after aging. Furthermore, the strength of the FRCs demonstrated a crescendo-decrescendo tendency with SiO2 nanofilm thickness increasing. The SBS results also showed that Group D had outstanding performance. Moreover, the results of cytotoxicity experiments such as cck8, LDH and Elisa, etc., showed that the FRCs have good cytocompatibility. Changing the number of ALD reaction cycles affects the mechanical properties of FRCs, which may be related to the stress relaxation and fracture between SiO2 nanofilm layers and the built-up internal stresses in the nanofilms. Eventually, the SiO2 nanofilms could enhance the FRCs' mechanical properties and performance to enamel by improving the interfacial bonding strength, and have good cytocompatibility.

Enhancing Radiotherapy Bolus Characteristics through Comparative Analysis of Added Sawdust and Bagasse Powder: A Comprehensive Study of Physical and Mechanical Properties

Research has been successfully conducted on the manufacture of synthetic bolus for radiotherapy made of silicone rubber containing polydimethyl siloxane and alginate as well as the addition of bagasse and wood sawdust. The purpose of this study was to determine the characterization of radiotherapy bolus by analyzing the comparison of the addition of bagasse and wood sawdust through its physical and mechanical properties. The methods used in this research are bolus sample preparation, characterizations of physical and mechanical properties and analysis of characterizations results. From the physical properties, the results of the characterizations of this research obtained that in the density test the bolus synthesis with the addition of bagasse at a thickness of 1.5 cm and 2 cm was 0.6 g/cm3 and 0.55 g/cm3 respectively, while the bolus synthesis with the addition of wood sawdust at a thickness of 1.5 cm and 2 cm had a density of 0.86 g/cm3 and 0.75 g/cm3 respectively. In porosity testing, the 1.5 cm thick synthetic bolus with the addition of bagasse and wood sawdust has a porosity of 6.6% while the bolus with a thickness of 2 cm in the addition of bagasse and wood sawdust has a porosity of 5%. In the water absorption test, the synthetic bolus in the addition of bagasse with a thickness of 1.5 cm and 2 cm has a water absorption of 11.11% and 9.09%, respectively. Bolus synthesis with the addition of wood sawdust with a thickness of 1.5 cm and 2 cm had a water absorption of 7.69% and 6.66%, respectively. From the mechanical properties, tensile strength testing of the synthesized bolus of 1.5 cm and 2 cm thickness with the addition of bagasse has a tensile strength value of 0.56 MPa and 0.38 MPa, respectively. while the tensile strength of the synthesized bolus with the addition of wood sawdust of 1.5 cm and 2 cm thickness is 0.42 MPa and 0.33 MPa, respectively. In the elongation at break test, the synthesis bolus with the addition of bagasse at a thickness of 1.5 cm and 2 cm was 92.33%, 52.69% respectively and the bolus with the addition of wood sawdust at a thickness of 1.5 cm and 2 cm had a large elongation at break of 93.49% and 106%. And in the elastic modulus test, the synthesis bolus in the addition of bagasse with a thickness of 1.5 cm and 2 cm is 0.611 MPa and 0.723 MPa respectively while the elastic modulus in the synthesis bolus with the addition of wood sawdust with a thickness of 1.5 cm and 2 cm is 0.465 MPa and 0.319 MPa respectively. From the physical and mechanical tests that have been carried out, the synthetic bolus with the addition of bagasse and wood sawdust at a thickness of 1.5 cm given the codes A1 and B1 can be said to have good material and has high elasticity compared to the synthetic bolus with a thickness of 2 cm both from the addition of bagasse and wood sawdust given the codes A2 and B2.

Characterization of Mechanical Properties of Welds of Q355D Steel by DSI Technique

Characterization of Mechanical Properties of Welds of Q355D Steel by DSI Technique

Variability of intervertebral joint stiffness between specimens and spine levels.

Introduction: Musculoskeletal multibody models of the spine can be used to investigate the biomechanical behaviour of the spine. In this context, a correct characterisation of the passive mechanical properties of the intervertebral joint is crucial. The intervertebral joint stiffness, in particular, is typically derived from the literature, and the differences between individuals and spine levels are often disregarded. Methods: This study tested if an optimisation method of personalising the intervertebral joint stiffnesses was able to capture expected stiffness variation between specimens and between spine levels and if the variation between spine levels could be accurately captured using a generic scaling ratio. Multibody models of six T12 to sacrum spine specimens were created from computed tomography data. For each specimen, two models were created: one with uniform stiffnesses across spine levels, and one accounting for level dependency. Three loading conditions were simulated. The initial stiffness values were optimised to minimize the kinematic error. Results: There was a range of optimised stiffnesses across the specimens and the models with level dependent stiffnesses were less accurate than the models without. Using an optimised stiffness substantially reduced prediction errors. Discussion: The optimisation captured the expected variation between specimens, and the prediction errors demonstrated the importance of accounting for level dependency. The inaccuracy of the predicted kinematics for the level-dependent models indicated that a generic scaling ratio is not a suitable method to account for the level dependency. The variation in the optimised stiffnesses for the different loading conditions indicates personalised stiffnesses should also be considered load-specific.

Integrated Geotechnical and Electrical Resistivity Tomography to Map the Lithological Variability Involved and Breaking Surface Evolution in Landslide Context: A Case Study of the Targa Ouzemour (Béjaia)

The specific lithology of the southern part of Bejaia city represents a major limitation to urban settlement and expansion. This is partly due to landslides that tend to affect this region. To date, one of these landslides in this region has occurred in the Targa Ouzemour area, where the damage extended approximately six hectares. The main purpose of this study is to identify the failure surfaces characterizing the internal structure of this landslide as well as the significant influence of groundwater on slope instability, which manifests as surface cracking and subsidence. We have combined several geotechnical and geophysical methods, including field observations. The exploitation of the collected geotechnical data from the six (06) boreholes drilled in the landslide zone has allowed for knowledge to be gained on the lithological components, as well as the characterizations of physical and mechanical properties on a range of different types of affected rocks, whereas electrical resistivity tomography (ERT) data allowed an in-depth examination, leading us to reconstruct the landslide geometry and particularly to evaluate the hydrological characteristics of the studied site. Moreover, the resistivity contrast patterns provided more clarity to discern between the various lithological formations that are still stable or actively moving within this landslide. All these findings have contributed to the construction of a characteristic geomodel that highlights the failure surfaces over which displacement is still experienced. Finally, with the evidence of rainfall effects on the deformation and stability of the slope, specific landslide remedial measures were accordingly suggested.