763 results match your criteria strength microhardness

Methacrylate-functionalized proanthocyanidins as novel polymerizable collagen cross-linkers - Part 2: Effects on polymerization, microhardness and leaching of adhesives.

Dent Mater 2021 May 5. Epub 2021 May 5.

School of Dentistry, University of Missouri - Kansas City, Kansas City, MO, 64108, USA. Electronic address:

Objective: The aim of the study was to investigate the effects of a novel polymerizable collagen cross-linker methacrylate-functionalized proanthocyanidins (MAPA) on the polymerization, microhardness and leaching of a HEMA-based experimental dental adhesive system.

Methods: Three MAPAs were synthesized using different methacrylate (MA) to proanthocyanidins (PA) feeding ratios of 1:2, 1:1, and 2:1 to obtain MAPA-1, MAPA-2, and MAPA-3, respectively. The resulting three MAPAs and PA were added to an experimental adhesive formulated with HEMA and a tri-component photoinitiator system (0. Read More

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Low velocity oxy fuel spraying of hydroxyapatite coating on a multifunctional UNS S31254 austenitic stainless steel.

Proc Inst Mech Eng H 2021 May 7:9544119211015770. Epub 2021 May 7.

Department of Mechanical Engineering, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, Uttar Pradesh, India.

Artificial material such as stainless steel (SS) is widely used for orthopaedic applications owing to its superior properties, ease of fabrication and lower cost. However, in the body environment, stainless steel can leach toxic elements such as nickel and chromium. To prevent this, a hydroxyapatite (HAp) coating having chemical characteristics very similar to the human bone was deposited on a medical-grade UNS S31254 austenitic stainless steel by a Low-velocity oxy-fuel spray gun (LVOF). Read More

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Characterization of the Structure, Mechanical Properties and Erosive Resistance of the Laser Cladded Inconel 625-Based Coatings Reinforced by TiC Particles.

Materials (Basel) 2021 Apr 26;14(9). Epub 2021 Apr 26.

Welding Department, Faculty of Mechanical Engineering, Silesian University of Technology, Konarskiego Street 18A, 44-100 Gliwice, Poland.

The article presents research in the field of laser cladding of metal-matrix composite (MMC) coatings. Nickel-based superalloys show attractive properties including high tensile strength, fatigue resistance, high-temperature corrosion resistance and toughness, which makes them widely used in the industry. Due to the insufficient wear resistance of nickel-based superalloys, many scientists are investigating the possibility of producing nickel-based superalloys matrix composites. Read More

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Enhanced Mechanical, Thermal and Antimicrobial Properties of Additively Manufactured Polylactic Acid with Optimized Nano Silica Content.

Nanomaterials (Basel) 2021 Apr 15;11(4). Epub 2021 Apr 15.

Department of Manufacturing & Civil Engineering, NTNU-Norwegian University of Science and Technology, Building B', Teknologivegen 22, 2815 Gjøvik, Norway.

The scope of this work was to create, with melt mixing compounding process, novel nanocomposite filaments with enhanced properties that industry can benefit from, using commercially available materials, to enhance the performance of three-dimensional (3D) printed structures fabricated via fused filament fabrication (FFF) process. Silicon Dioxide (SiO) nanoparticles (NPs) were selected as fillers for a polylactic acid (PLA) thermoplastic matrix at various weight % (wt.%) concentrations, namely, 0. Read More

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Effect of Silicon Nitride and Graphene Nanoplatelets on the Properties of Aluminum Metal Matrix Composites.

Materials (Basel) 2021 Apr 10;14(8). Epub 2021 Apr 10.

Center for Advanced Materials (CAM), Qatar University, 2713 Doha, Qatar.

This research work aims at investigating the influence of a fixed content of silicon nitride (SiN) and varied contents of graphene nanoplatelets (GNPs) on the physical (density, structural, morphological) and mechanical properties (microhardness, nanoindentation) of Al-SiN-GNPs composites. The composites were fabricated by a microwave-assisted powder metallurgy route. The SiN concentration was fixed at (5 wt. Read More

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Statistical and Microstructural Analyses of Al-C-Cu Composites Synthesized Using the State Solid Route.

Materials (Basel) 2021 Apr 14;14(8). Epub 2021 Apr 14.

Centro de Investigación en Materiales Avanzados (CIMAV), Departamento de Metalurgia e Integridad Estructural, Miguel de Cervantes No. 120, Chihuahua 31109, Mexico.

Aluminum powder with different C and C-Cu mixtures powders were fabricated by powder metallurgy, using high-energy mechanical milling as a pre-treatment of powders. To evaluate the combined effect of the C-Cu mixture and the process conditions, such as sintering temperature/time and milling time, on the yield stress and hardness, two experimental designs were carried out. The results were analyzed with Minitab Statistical Software using contour plots. Read More

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The Influence of Scandium on the Composition and Structure of the Ti-Al Alloy Obtained by "Hydride Technology".

Nanomaterials (Basel) 2021 Apr 3;11(4). Epub 2021 Apr 3.

Chemical Technology Laboratory, National Research Tomsk State University, 36 Lenin Avenue, 634050 Tomsk, Russia.

In this study the influence of scandium on the structural and phase state of the Ti-Al alloy obtained by the method of "Hydride Technology" (HT). The Rietveld method has allowed for determining the content of basic phases of the 49at.%Ti-49at. Read More

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Effect of Protein-Based Treatment on Chemical Composition, Hardness and Bond Strength of Remineralized Enamel.

Braz Dent J 2021 Jan-Feb;32(1):85-90

Department of Restorative Dentistry, School of Dentistry, UNOPAR - Universidade Norte do Paraná, Londrina, PR, Brazil.

This study evaluated the chemical composition and microhardness of human enamel treated with an Enamel Matrix Derivative (EMD) solution, and the bond strength between composite resin and this enamel. Thirty human enamel samples were randomly divided into three groups: Untouched Enamel (UE), Demineralized Enamel (DE) and Demineralized Enamel Treated with EMD (ET). DE and ET groups were subjected to acid challenge and ET treated with EMD (EMD was directly applied over conditioned enamel and left for 15 min). Read More

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Sesame Oil () as a New Challenge for Reinforcement of Conventional Glass Ionomer Cement, Could It Be?

Neven S Aref

Int J Dent 2021 22;2021:5516517. Epub 2021 Mar 22.

Department of Dental Biomaterials, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.

Purpose: Despite the advantages of glass ionomer cement (GIC) including chemical bonding to the tooth structure and fluoride release, its low-grade mechanical properties make it a topic for research. Accordingly, this study was conducted to assess the ability of sesame oil as a natural bioactive additive to reinforce conventional glass ionomer cement.

Materials And Methods: Sesame oil was blended into the liquid component of the cement in ratios of 3 and 5 (v/v%). Read More

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Fine-tuning of mechanical properties in a Zn-Ag-Mg alloy via cold plastic deformation process and post-deformation annealing.

Bioact Mater 2021 Oct 21;6(10):3424-3436. Epub 2021 Mar 21.

AGH University of Science and Technology, Faculty of Metals Engineering and Industrial Computer Science, Al. A. Mickiewicza 30, 30-059 Krakow, Poland.

In recent years, Zn-based materials have been extensively investigated as potential candidates for biodegradable implant applications. The introduction of alloying elements providing solid-solution strengthening and second phase strengthening seems crucial to provide a suitable platform for the thermo-mechanical strengthening of Zn alloys. In this study, a systematic investigation of the microstructure, crystallographic texture, phase composition, and mechanical properties of a Zn-3Ag-0. Read More

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October 2021

The Performance of CR180IF and DP600 Laser Welded Steel Sheets under Different Strain Rates.

Materials (Basel) 2021 Mar 22;14(6). Epub 2021 Mar 22.

Faculty of Materials, Metallurgy and Recycling, Technical University of Košice, Letná 9, 042 00 Košice, Slovakia.

The presented research background is a car body manufacturer's request to test the car body's components welded from dissimilar steel sheets. In view of the vehicle crew's protection, it is necessary to study the static and dynamic behavior of welded steels. Therefore, the influence of laser welding on the mechanical and dynamical properties, microstructure, microhardness, and welded joint surface roughness of interstitial free CR180IF and dual-phase DP600 steels were investigated. Read More

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Properties of WC-10%Co-4%Cr Detonation Spray Coating Deposited on the Al-4%Cu-1%Mg Alloy.

Materials (Basel) 2021 Mar 4;14(5). Epub 2021 Mar 4.

Department of Materials Science, Physical and Chemical Properties of Materials, South Ural State University, 76 Lenin Av., Chelyabinsk 454080, Russia.

One of the methods of local improvement of the wear resistance of aluminum alloy parts is the deposition of hard tungsten carbide-based coatings on the surfaces subjected to intense external influence. This paper is devoted to the characterization of the WC-10Co-4Cr (wt.%) coating deposited on an Al-4Cu-1Mg (wt. Read More

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Characterization of an Experimental Two-Step Self-Etch Adhesive's Bonding Performance and Resin-Dentin Interfacial Properties.

Polymers (Basel) 2021 Mar 25;13(7). Epub 2021 Mar 25.

Department of Restorative Dentistry, Graduate School of Dental Medicine, Hokkaido University, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan.

This study evaluated an experimental two-step self-etch adhesive (BZF-29, BZF) by comparing it with a reference two-step self-etch adhesive (Clearfil Megabond 2, MB) and a universal adhesive (G-Premio Bond, GP) for microtensile bond strength (μTBS) and resin-dentin interfacial characteristics. Twenty-four human third molars were used for the μTBS test. Bonded peripheral dentin slices were separated to observe the resin-dentin interface and measure the adhesive layer thickness with SEM. Read More

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Microstructure Evolution and Strengthening Mechanism of Galvanized Steel/Mg Alloy Joint Obtained by Ultrasonic Vibration-Assisted Welding Process.

Materials (Basel) 2021 Mar 29;14(7). Epub 2021 Mar 29.

College of Materials Science and Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China.

A novel ultrasonic vibration-assisted welding (UVAW) process was used to achieve reliable joining of galvanized steel and Mg alloy. The effects of the UVAW technique on the microstructure and mechanical properties of galvanized steel/Mg alloy weldment were studied in detail. The introduction of ultrasonic vibration can ameliorate the wetting of welds and eliminate porosity defects. Read More

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Numerical Simulation and Experimental Study on Compound Casting of Layered Aluminum Matrix Composite Brake Drum.

Materials (Basel) 2021 Mar 15;14(6). Epub 2021 Mar 15.

National Engineering & Technology Research Center for Non-Ferrous Metal Matrix Composites, GRINM Group Co., Ltd., No.11, Xingke East Street, Yanqi Economic Development Zone, Huairou District, Beijing 101407, China.

The requirements of high-strength, wear-resistance and lightweight of brake drums have been continually increasing in recent years and any specific aluminum alloy or particle-reinforced aluminum matrix composites may not satisfy all the demands. Combining dissimilar materials to play their respective advantages is a solution to this problem. In this study, a compound casting method was used to combine solid SiC/A357 composite and a liquid 7050 aluminum alloy to prepare an aluminum matrix composite with a layered structure. Read More

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Sustainable Additive Manufacturing: Mechanical Response of Polyethylene Terephthalate Glycol over Multiple Recycling Processes.

Materials (Basel) 2021 Mar 2;14(5). Epub 2021 Mar 2.

Mechanical Engineering Department, Hellenic Mediterranean University, 71410 Heraklion, Greece.

The continuous demand for thermoplastic polymers in a great variety of applications, combined with an urgent need to minimize the quantity of waste for a balanced energy-from-waste strategy, has led to increasing scientific interest in developing new recycling processes for plastic products. Glycol-modified polyethylene terephthalate (PETG) is known to have some enhanced properties as compared to polyethylene terephthalate (PET) homopolymer; this has recently attracted the interest from the fused filament fabrication (FFF) three-dimensional (3D) printing community. PET has shown a reduced ability for repeated recycling through traditional processes. Read More

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Can silver diamine fluoride or silver nanoparticle-based anticaries agents to affect enamel bond strength?

Restor Dent Endod 2021 Feb 12;46(1):e7. Epub 2021 Jan 12.

Department of Restorative Dentistry, School of Dentistry, University of North Parana, Londrina, PR, Brazil.

Objectives: The aim of the current study is to investigate the effect of different anticaries agents, such as experimental agents based on silver nanoparticles (SNPs) and silver diamine fluoride (SDF), on the micro-shear bond strength (μ-SBS) of composite resin applied to intact enamel (IE) or demineralized enamel (DE).

Materials And Methods: Sixty dental enamel fragments were collected from human third molars and categorized into 6 groups ( = 10): positive control (IE), negative control (DE), IE + SDF, DE + SDF, IE + SNP and DE + SNP. Samples from DE, DE + SDF and DE + SNP groups were subjected to pH cycling; superficial microhardness test was performed to confirm demineralization. Read More

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February 2021

Flexural strength and microhardness of bulk-fill restorative materials.

J Esthet Restor Dent 2021 Mar 5. Epub 2021 Mar 5.

Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil.

Background: Bulk-fill materials can facilitate the restorative procedure mainly for deep and wide posterior cavities. The purpose of this study was to evaluate flexural strength (biaxial flexural strength [BFS]) and microhardness (Knoop microhardness [KHN]) at different depths of bulk-fill materials.

Methods: Five bulk-fill materials were tested: two light-curable composite resins, one dual-cure composite, one bioactive restorative, and a high-viscosity glass ionomer. Read More

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Calcium Silicate-Based Biocompatible Light-Curable Dental Material for Dental Pulpal Complex.

Nanomaterials (Basel) 2021 Feb 27;11(3). Epub 2021 Feb 27.

Institute of Tissue Regeneration Engineering (ITREN), Dankook University, 119 Dandae-ro, Cheonan 31116, Chungcheongnam-do, Korea.

Dental caries causes tooth defects and clinical treatment is essential. To prevent further damage and protect healthy teeth, appropriate dental material is a need. However, the biocompatibility of dental material is needed to secure the oral environment. Read More

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February 2021

Development of 3D printed resin reinforced with modified ZrO nanoparticles for long-term provisional dental restorations.

Dent Mater 2021 Mar 1. Epub 2021 Mar 1.

UWA Dental School, University of Western Australia, 17 Monash Avenue, Nedlands WA 6009, Australia. Electronic address:

Objective: To characterize and investigate efficacy of loading functionalized ZrO nanoparticles in 3-dimensional (3D) printed acrylate ester-based resin subjected to accelerated aging in artificial saliva. As well as to evaluate the effect of ZrO nanoparticle volume fraction addition on mechanical and physical properties of printed composite.

Methods: Functionalized ZrO nanoparticles were characterized using TEM and Raman spectroscopy. Read More

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Effects of alternatively used thermal treatments on the mechanical and fracture behavior of dental resin composites with varying filler content.

J Mech Behav Biomed Mater 2021 05 25;117:104424. Epub 2021 Feb 25.

Department of Conservative Dentistry, School of Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil; Graduate Program in Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil. Electronic address:

The purpose of this study was two-fold: (i) to investigate whether the thermal treatment of direct dental resin composites (RCs) using microwave or autoclave heating cycles would modify the materials' strength as compared to the protocol without heating (control); and (ii) to compare the mechanical performance of direct and indirect RCs. Three RCs (from 3M ESPE) were tested: one indirect (Sinfony); and two direct materials (microhybrid - Filtek Z250; and nanofilled - Filtek Z350). Specimens from the direct RCs were prepared and randomly allocated into three groups according to the thermal treatment (n = 10): Control - no thermal treatment was performed; Microwave - the wet heating was performed using a microwave oven; and Autoclave - the wet heating was performed in an autoclave oven. Read More

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Antimicrobial properties, mechanics, and fluoride release of ionomeric cements modified by red propolis.

Angle Orthod 2021 Feb 25. Epub 2021 Feb 25.

Objectives: To evaluate the antimicrobial activity, mechanical properties, and fluoride release capacity of glass ionomer cement (GIC) used for cementing orthodontic bands and modified by ethanolic extract of red propolis (EERP) in different concentrations.

Materials And Methods: Two orthodontic GICs containing EERP at 10%, 25%, and 50%, were used. The following assays were carried out: cell viability tests against Streptococcus mutans and Candida albicans, diametral tensile strength, compressive strength, shear bond strength, microhardness, and fluoride release capacity. Read More

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February 2021

Hydroxy acids for adhesion to enamel and dentin: Long-term bonding performance and effect on dentin biostability.

J Dent 2021 04 19;107:103613. Epub 2021 Feb 19.

Department of General Dental Sciences, School of Dentistry, Marquette University, Milwaukee, WI, United States.

Objectives: To test the demineralization potential, bonding performance, and dentin biostability when using hydroxy acids for etching enamel and dentin.

Methods: Surface microhardness, roughness and depth of demineralization were investigated after etching enamel and dentin with 35 % glycolic acid (Gly), tartaric acid (Ta), gluconic acid (Glu), gluconolactone (Gln), or phosphoric acid (Pa) (n = 5/group). Dentin microtensile bond strength (μTBS) after 24 h or 1 year of bonding (n = 8 teeth/group) and enamel shear bond strength (SBS) after 24 h (n = 10 teeth/group) were obtained. Read More

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Consensus on glass-ionomer cement thresholds for restorative indications.

J Dent 2021 04 18;107:103609. Epub 2021 Feb 18.

Queen Mary University of London, Mile End Rd, Bethnal Green, London E1 4NS, England, United Kingdom.

Objective: The aim of this paper is to present the results of a consensus meeting on the threshold property requirements for the clinical use of conventional glass-ionomer cements (GICs) for restorative indications.

Methods: Twenty-one experts on GICs evaluated the results of tests on mechanical and optical properties of 18 different brands of restorative GICs: Bioglass R [B], Chemfil Rock [CR], Equia Forte [EF], Gold Label 2 [GL2], Gold Label 9 [GL9], Glass Ionomer Cement II [GI], Ionglass [IG], Ion Z [IZ], Ionomaster [IM], Ionofil Plus [IP], Ionostar Plus [IS], Ketac Molar Easymix [KM], Magic Glass [MG], Maxxion R [MA], Riva Self Cure [R], Vidrion R [V], Vitro Fil [VF] and Vitro Molar [VM]. All experiments were carried out by a team of researchers from Brazil and England following strict protocols, under the same laboratory conditions throughout, and maintaining data integrity. Read More

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Impact of laser parameters on additively manufactured cobalt-chromium restorations.

J Prosthet Dent 2021 Feb 17. Epub 2021 Feb 17.

Professor and Dean, Faculty of Machine Building, Technical University of Cluj-Napoca, Cluj-Napoca, Romania.

Statement Of Problem: The selective laser melting (SLM) process has become popular for the fabrication of frameworks for metal-ceramic restorations, although their surface roughness is greater than with cast or milled frameworks. Limited information is available regarding the surface mechanical characteristics of cobalt-chromium (Co-Cr) SLM-manufactured restorations.

Purpose: The purpose of this in vitro study was to adapt the laser parameters for a remelting strategy, scanning the outer boundary of Co-Cr specimens, to reduce surface roughness and solidification defects, to determine microhardness, to investigate surface morphology and microstructure, and to establish surface mechanical characteristics. Read More

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February 2021

Microstructural evolution of tantalum nitride thin films synthesized by inductively coupled plasma sputtering.

Appl Microsc 2020 Feb 27;50(1). Epub 2020 Feb 27.

Research Institute of Advanced Materials, Department of Materials Science and Engineering, Seoul National University, 1 Gwanak-ro Gwanak-gu, Seoul, Republic of Korea.

Tantalum nitride (TaN) thin films were grown utilizing an inductively coupled plasma (ICP) assisted direct current (DC) sputtering, and 20-100% improved microhardness values were obtained. The detailed microstructural changes of the TaN films were characterized utilizing transmission electron microscopy (TEM), as a function of nitrogen gas fraction and ICP power. As nitrogen gas fraction increases from 0. Read More

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February 2020

Influence of Compositionally Graded Interface on Microstructure and Compressive Deformation of 316L Stainless Steel to Al12Si Aluminum Alloy Bimetallic Structures.

ACS Appl Mater Interfaces 2021 Feb 11;13(7):9174-9185. Epub 2021 Feb 11.

W. M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164-2920, United States.

Bimetallic structures offer properties that can be customized based on applications, manufactured in one operation. Such manufacturing options are fascinating, as joining two metallic materials, especially for two dissimilar metals without significant defects, is challenging. In this study, 316L stainless steel (SS) to Al12Si aluminum alloy structures were processed, tailoring the compositionally graded interface on a SS 316 substrate using a directed energy deposition (DED)-based additive manufacturing (AM) process. Read More

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February 2021

Interfacial Adhesion of a Semi-Interpenetrating Polymer Network-Based Fiber-Reinforced Composite with a High and Low-Gradient Poly(methyl methacrylate) Resin Surface.

Polymers (Basel) 2021 Jan 22;13(3). Epub 2021 Jan 22.

Dental Biomaterials Research Chair, College of Applied Medical Sciences, King Saud University, Riyadh 10219, Saudi Arabia.

The research aimed to determine the tensile bond strength (TBS) between polymerized intact and ground fiber-reinforced composite (FRC) surfaces. FRC prepregs (a reinforcing fiber pre-impregnated with a semi-interpenetrating polymer network (semi-IPN) resin system; everStick C&B) were divided into two groups: intact FRCs (with a highly PMMA-enriched surface) and ground FRCs (with a low PMMA gradient). Each FRC group was treated with: StickRESIN and G-Multi PRIMER. Read More

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January 2021

Microstructure and Mechanical Properties of Laser-Welded DP Steels Used in the Automotive Industry.

Materials (Basel) 2021 Jan 19;14(2). Epub 2021 Jan 19.

Division of Material Science, Luleå University of Technology, 971 87 Luleå, Sweden.

The aim of this work was to investigate the microstructure and the mechanical properties of laser-welded joints combined of Dual Phase DP800 and DP1000 high strength thin steel sheets. Microstructural and hardness measurements as well as tensile and fatigue tests have been carried out. The welded joints (WJ) comprised of similar/dissimilar steels with similar/dissimilar thickness were consisted of different zones and exhibited similar microstructural characteristics. Read More

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January 2021

Incorporation of Chitosan Nanoparticles into a Cold-Cure Ortho-Dontic Acrylic Resin: Effects on Mechanical Properties.

Biomimetics (Basel) 2021 Jan 15;6(1). Epub 2021 Jan 15.

Dental Research Center, Mashhad University of Medical Sciences, Mashhad 9177948959, Iran.

Improvement of the antibacterial properties of acrylic resins, used in the construction of removable orthodontic appliances, is an important strategy to reduce the incidence of caries and oral diseases in orthodontic treatments. The addition of antimicrobial agents to acrylic resins is one of the effective methods to enhance the antimicrobial properties of these materials. However, one main concern is that modification of acrylic resin has negative effects on its mechanical properties. Read More

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January 2021