keyword
MENU ▼
Read by QxMD icon Read
search

fracture toughness

keyword
https://www.readbyqxmd.com/read/28747764/super-strong-dislocation-structured-high-carbon-martensite-steel
#1
Jun-Jie Sun, Yong-Ning Liu, Yun-Tian Zhu, Fu-Liang Lian, Hong-Ji Liu, Tao Jiang, Sheng-Wu Guo, Wen-Qing Liu, Xiao-Bing Ren
High-carbon martensite steels (with C > 0.5 wt.%) are very hard but at the same time as brittle as glass in as-quenched or low-temperature-tempered state. Such extreme brittleness, originating from a twin microstructure, has rendered these steels almost useless in martensite state. Therefore, for more than a century it has been a common knowledge that high-carbon martensitic steels are intrinsically brittle and thus are not expected to find any application in harsh loading conditions. Here we report that these brittle steels can be transformed into super-strong ones exhibiting a combination of ultrahigh strength and significant toughness, through a simple grain-refinement treatment, which refines the grain size to ~4 μm...
July 26, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28740563/the-impact-of-ti-and-temperature-on-the-stability-of-nb5si3-phases-a-first-principles-study
#2
Ioannis Papadimitriou, Claire Utton, Panos Tsakiropoulos
Nb-silicide based alloys could be used at T > 1423 K in future aero-engines. Titanium is an important additive to these new alloys where it improves oxidation, fracture toughness and reduces density. The microstructures of the new alloys consist of an Nb solid solution, and silicides and other intermetallics can be present. Three Nb5Si3 polymorphs are known, namely αNb5Si3 (tI32 Cr5B3-type, D8l), βNb5Si3 (tI32 W5Si3-type, D8m) and γNb5Si3 (hP16 Mn5Si3-type, D88). In these 5-3 silicides Nb atoms can be substituted by Ti atoms...
2017: Science and Technology of Advanced Materials
https://www.readbyqxmd.com/read/28714141/intrinsic-3d-prestressing-a-new-route-for-increasing-strength-and-improving-toughness-of-hybrid-inorganic-biocements
#3
Martha Schamel, Jake E Barralet, Michael Gelinsky, Jürgen Groll, Uwe Gbureck
Cement is the most consumed resource and is the most widely used material globally. The ability to extrinsically prestress cementitious materials with tendons usually made from steel allows the creation of high-strength bridges and floors from this otherwise brittle material. Here, a dual setting cement system based on the combination of hydraulic cement powder with an aqueous silk fibroin solution that intrinsically generates a 3D prestressing during setting, dramatically toughening the cement to the point it can be cut with scissors, is reported...
July 17, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28708001/applying-full-spectrum-analysis-to-a-raman-spectroscopic-assessment-of-fracture-toughness-of-human-cortical-bone
#4
Alexander J Makowski, Mathilde Granke, Oscar D Ayala, Sasidhar Uppuganti, Anita Mahadevan-Jansen, Jeffry S Nyman
A decline in the inherent quality of bone tissue is a † Equal contributors contributor to the age-related increase in fracture risk. Although this is well-known, the important biochemical factors of bone quality have yet to be identified using Raman spectroscopy (RS), a nondestructive, inelastic light-scattering technique. To identify potential RS predictors of fracture risk, we applied principal component analysis (PCA) to 558 Raman spectra (370-1720 cm(-1)) of human cortical bone acquired from 62 female and male donors (nine spectra each) spanning adulthood (age range = 21-101 years)...
January 1, 2017: Applied Spectroscopy
https://www.readbyqxmd.com/read/28701718/recycling-and-self-healing-of-polybenzoxazines-with-dynamic-sulfide-linkages
#5
Mustafa Arslan, Baris Kiskan, Yusuf Yagci
In this work, a recycling and self-healing strategy for polybenzoxazines through both S-S bond cleavage-reformation reaction and supramolecular attractions is described. Both recyclable and self-healable polybenzoxazines can be prepared from low cost chemicals with a simple procedure in only 30 minutes. For this purpose, inverse vulcanization of poly(propylene oxide)benzoxazine (PPOB) and diallybenzoxazine (B-al) with elemental sulfur was performed at 185 °C. The obtained cross-linked polymer films exhibited thermally driven recycling ability up to 5 cycles...
July 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28675848/the-micro-damage-process-zone-during-transverse-cortical-bone-fracture-no-ears-at-crack-growth-initiation
#6
Thomas Willett, David Josey, Rick Xing Ze Lu, Gagan Minhas, John Montesano
OBJECTIVE: Apply high-resolution benchtop micro-computed tomography (micro-CT) to gain greater understanding and knowledge of the formation of the micro-damage process zone formed during traverse fracture of cortical bone. METHODS: Bovine cortical bone was cut into single edge notch (bending) fracture testing specimens with the crack on the transverse plane and oriented to grow in the circumferential direction. We used a multi-specimen technique and deformed the specimens to various individual secant modulus loss levels (P-values) up to and including maximum load (Pmax)...
June 24, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28674436/photonics-and-fracture-toughness-of-heterogeneous-composite-materials
#7
S Joseph Antony, George Okeke, D Deniz Tokgoz, N Gozde Ozerkan
Fracture toughness measures the resistance of a material to fracture. This fundamental property is used in diverse engineering designs including mechanical, civil, materials, electronics and chemical engineering applications. In spite of the advancements made in the past 40 years, the evaluation of this remains challenging for extremely heterogeneous materials such as composite concretes. By taking advantage of the optical properties of a thin birefringent coating on the surface of opaque, notched composite concrete beams, here we sense the evolution of the maximum shear stress distribution on the beams under loading...
July 3, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28665405/damage-tolerance-of-nuclear-graphite-at-elevated-temperatures
#8
Dong Liu, Bernd Gludovatz, Harold S Barnard, Martin Kuball, Robert O Ritchie
Nuclear-grade graphite is a critically important high-temperature structural material for current and potentially next generation of fission reactors worldwide. It is imperative to understand its damage-tolerant behaviour and to discern the mechanisms of damage evolution under in-service conditions. Here we perform in situ mechanical testing with synchrotron X-ray computed micro-tomography at temperatures between ambient and 1,000 °C on a nuclear-grade Gilsocarbon graphite. We find that both the strength and fracture toughness of this graphite are improved at elevated temperature...
June 30, 2017: Nature Communications
https://www.readbyqxmd.com/read/28662861/the-influence-of-y-tzp-surface-treatment-on-topography-and-ceramic-resin-cement-interfacial-fracture-toughness
#9
P N G Paes, F L Bastian, P M Jardim
OBJECTIVE: Consider the efficacy of glass infiltration etching (SIE) treatment as a procedure to modify the zirconia surface resulting in higher interfacial fracture toughness. METHODS: Y-TZP was subjected to 5 different surface treatments conditions consisting of no treatment (G1), SIE followed by hydrofluoric acid treatment (G2), heat treated at 750°C (G3), hydrofluoric acid treated (G4) and airborne-particle abrasion with alumina particles (G5). The effect of surface treatment on roughness was evaluated by Atomic Force Microscopy providing three different parameters: Ra, Rsk and surface area variation...
June 26, 2017: Dental Materials: Official Publication of the Academy of Dental Materials
https://www.readbyqxmd.com/read/28645511/lamellae-spatial-distribution-modulates-fracture-behavior-and-toughness-of-african-pangolin-scales
#10
Michael J Chon, Matthew Daly, Bin Wang, Xianghui Xiao, Alireza Zaheri, Marc A Meyers, Horacio D Espinosa
Pangolin scales form a durable armor whose hierarchical structure offers an avenue towards high performance bio-inspired materials design. In this study, the fracture resistance of African pangolin scales is examined using single edge crack three-point bend fracture testing in order to understand toughening mechanisms arising from the structures of natural mammalian armors. In these mechanical tests, the influence of material orientation and hydration level are examined. The fracture experiments reveal an exceptional fracture resistance due to crack deflection induced by the internal spatial orientation of lamellae...
June 10, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28642921/fracture-behavior-of-single-structure-fiber-reinforced-composite-restorations
#11
Kohji Nagata, Sufyan K Garoushi, Pekka K Vallittu, Noriyuki Wakabayashi, Hidekazu Takahashi, Lippo V J Lassila
Objective: The applications of single-structure fiber-reinforced composite (FRC) in restorative dentistry have not been well reported. This study aimed to clarify the static mechanical properties of anterior crown restorations prepared using two types of single-structure FRC. Materials and methods: An experimental crown restoration was designed for an upper anterior incisor. The restorations were made from IPS Empress CAD for CEREC (Emp), IPS e.max(®) CAD (eMx), experimental single-structure all-FRC (a-FRC), Filtek™ Supreme XTE (XTE), and commercially available single-structure short-FRC (everX Posterior™) (n = 8 for each material) (s-FRC)...
December 2016: Acta Biomaterialia Odontologica Scandinavica
https://www.readbyqxmd.com/read/28639437/ultrasound-assisted-green-economic-synthesis-of-hydroxyapatite-nanoparticles-using-eggshell-bio-waste-and-study-of-mechanical-and-biological-properties-for-orthopaedic-applications
#12
Vijay H Ingole, Kamal Hany Hussein, Anil A Kashale, Kalyani Ghule, Tomaž Vuherer, Vanja Kokol, Jia-Yaw Chang, Yong-Chien Ling, Aruna Vinchurkar, Hom N Dhakal, Anil V Ghule
Nanostructured hydroxyapatite (HAp) is most favorable candidate biomaterial for bone tissue engineering because of its bioactive and osteoconductive properties. Herein, we report for the first time ultrasound assisted facile and economic approach for the synthesis of nanocrystalline hydroxyapatite (Ca10 (PO4 )6 (OH)2 ) using recycled eggshell bio-waste referred as EHAp. The process involves the reaction of eggshell bio-waste as a source of calcium and ammonium dihydrogen orthophosphate as a phosphate source...
June 22, 2017: Journal of Biomedical Materials Research. Part A
https://www.readbyqxmd.com/read/28638146/outstanding-compressive-creep-strength-in-cr-ir-codoped-mo0-85nb0-15-si2-crystals-with-the-unique-cross-lamellar-microstructure
#13
Koji Hagihara, Takaaki Ikenishi, Haruka Araki, Takayoshi Nakano
A (Mo0.85Nb0.15)Si2 crystal with an oriented, lamellar, C40/C11b two-phase microstructure is a promising ultrahigh-temperature (UHT) structural material, but its low room-temperature fracture toughness and low high-temperature strength prevent its practical application. As a possibility to overcome these problems, we first found a development of unique "cross-lamellar microstructure", by the cooping of Cr and Ir. The cross-lamellar microstructure consists of a rod-like C11b-phase grains that extend along a direction perpendicular to the lamellar interface in addition to the C40/C11b fine lamellae...
June 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28628168/fracture-toughness-of-wet-and-dry-particulate-materials-comprised-of-colloidal-sized-particles-role-of-plastic-deformation
#14
Mitchell L Sesso, George V Franks
This work demonstrates a method of measuring the fracture toughness of particulate materials comprised of colloidal sized particles over a wide range of saturation. Diametral compression of cylinders containing flaws of controlled length was used to measure the mode I fracture toughness. The effect of degree of saturation on the fracture toughness of slip cast ceramic grade alumina (d50 = 0.7 μm) was investigated. Dry powder compacts have significantly lower fracture toughness than when the powder compact is nearly fully saturated...
July 21, 2017: Soft Matter
https://www.readbyqxmd.com/read/28618481/crack-propagation-through-disordered-materials-as-a-depinning-transition-a-critical-test-of-the-theory
#15
Laurent Ponson, Nadjime Pindra
The dynamics of a planar crack propagating within a brittle disordered material is investigated numerically. The fracture front evolution is described as the depinning of an elastic line in a random field of toughness. The relevance of this approach is critically tested through the comparison of the roughness front properties, the statistics of avalanches, and the local crack velocity distribution with experimental results. Our simulations capture the main features of the fracture front evolution as measured experimentally...
May 2017: Physical Review. E
https://www.readbyqxmd.com/read/28607203/hydrogen-enhanced-cracking-revealed-by-in-situ-micro-cantilever-bending-test-inside-environmental-scanning-electron-microscope
#16
Yun Deng, Tarlan Hajilou, Afrooz Barnoush
To evaluate the hydrogen (H)-induced embrittlement in iron aluminium intermetallics, especially the one with stoichiometric composition of 50 at.% Al, a novel in situ micro-cantilever bending test was applied within an environmental scanning electron microscope (ESEM), which provides both a full process monitoring and a clean, in situ H-charging condition. Two sets of cantilevers were analysed in this work: one set of un-notched cantilevers, and the other set with focused ion beam-milled notch laying on two crystallographic planes: (010) and (110)...
July 28, 2017: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
https://www.readbyqxmd.com/read/28602753/enhanced-toughening-of-the-crossed-lamellar-structure-revealed-by-nanoindentation
#17
Christopher L Salinas, Enrique Escobar de Obaldia, Chanhue Jeong, Jessica Hernandez, Pablo Zavattieri, David Kisailus
Gastropods shells have evolved to resist the threat of increasingly stronger predators that smash, peal, and crush their shells. Their shells are most commonly constructed from a crossed lamellar microstructure, which consists of an exquisitely architected arrangement of aragonitic mineral and organic encompassing at least four orders of hierarchy. It is this careful control of mineral and organic placement within the entire crossed lamellar structure that yields a four-order of magnitude increase in fracture toughness versus abiotic aragonite...
May 31, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28601650/tough-chitosan-hydrogel-based-on-purified-regeneration-and-alkaline-solvent-as-biomaterials-for-tissue-engineering-applications
#18
Shichao Bi, Zixian Bao, Xiaoyu Bai, Shihao Hu, Xiaojie Cheng, Xiguang Chen
The chitosan based on purified regeneration could be dissolved in 6wt% aqueous NaOH without freeze-thawing cycles and acetylation processing, and such a solution system was effective and different from other dissolving methods Upon heating, a tough hydrogel was constructed from the chitosan (purified regeneration) alkaline solution. The results of XRD, TEM, SEM and rheology analysis proved that chitosan easily aggregated in the solution and formed a nanofibers network to gelate at elevated temperature and concentration...
June 7, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28595102/a-comparative-study-of-progressive-wear-of-four-dental-monolithic-veneered-glass-ceramics
#19
Zhenzhen Zhang, Yuanping Yi, Xuesong Wang, Jiawen Guo, Ding Li, Lin He, Shaofeng Zhang
OBJECTIVES: This study evaluated the wear performance and wear mechanisms of four dental glass-ceramics, based on the microstructure and mechanical properties in the progressive wear process. METHODS: Bar (N = 40, n = 10) and disk (N = 32, n = 8) specimens were prepared from (A) lithium disilicate glass-ceramic (LD), (B) leucite reinforced glass-ceramic (LEU), (C) feldspathic glass-ceramic (FEL), and (D) fluorapatite glass-ceramic (FLU). The bar specimens were tested for three-point flexural strength, hardness, fracture toughness and elastic modulus...
May 30, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28594005/the-effect-of-stw-defects-on-the-mechanical-properties-and-fracture-toughness-of-pristine-and-hydrogenated-graphene
#20
Akarsh Verma, Avinash Parashar
Graphene is emerging as a versatile material with a diverse field of applications. Synthesis techniques for graphene introduce several topological defects such as vacancies, dislocations and Stone-Thrower-Wales (STW) defects. Among them STW defects are generated without deleting any atom from the lattice position, but are introduced by rotating single C-C bonds. In this article, molecular dynamics based simulations have been performed to study the effect of STW defects on the fracture toughness of pristine graphene as well as graphene with crack edges passivated with hydrogen atoms...
June 21, 2017: Physical Chemistry Chemical Physics: PCCP
keyword
keyword
120242
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"