Effect of Rare Earth Cerium on Yield Strength Anisotropy of Al-Li Alloy Sheet and Its Theoretical Prediction

Traceadditionofrareearthinto 2 0 90Al Lialloyisoneofthemeasurestoimproveitslowductilityandtoughness .Al Lialloysheetwithstrongcrystallo graphictexturehasbeenknowntohaveunusuallyhigheryieldstrengthanisotropythanconventionalalu minumalloys[1～3] .However ,ithasnotbeennormallyrecognizedsofarabouttheeffectofceriumonthisanisotropyofAl Lialloy .Someinvestigationsonheat treatableAl Lialloysshowthattheyieldstrengthanisotropyof 2 0 90sheetalloyisdefinitelyassociatedwiththevolumefractionofT1precipita…     

The Effect of Cooling Rate on the Strength of Sintered Fe—Cu Compacts

Abstract

The effect of cooling rate from the sintering temperature upon the tensile strength of compacts from a mixture of iron and copper powder was investigated. The compacts were pressed at 450 and 390 MPa and sintered in hydrogen at 1120°C for 40 min. The copper content of the compacts varied from 0 to 12%. For alloys with Cu content >4% the tensile strength was found to be strongly dependent upon the cooling rate in the temperature range between 850 and 600°C, with rapidly cooled specimens being considerably stronger. In specimens with 8%Cu the tensile strength increased from 206 to 343 MPa when the cooling rate was increased from 10 to 200 degC min^?1. In specimens with 2%Cu cooling rates above and below 600 degC min^?1 appear to influence the tensile strength. Possible explanations for the observed effects of cooling rate upon tensile strength in sintered Fe–Cu alloys are discussed.     

Effect of RE Oxide on Impact Toughness and Primary Structure of Surfacing Metal

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Effect of CeO2 on Microstructure and Bond Strength of Fe-Ni-Cr Alloy

The more extreme conditions in which metallicmaterials are required to work lead to the developmentof different surface modification materials, such asnickel based alloy, Fe based alloy and Co based al loy, etc. In general, these …     

Characteristics of Nitrogen Jet and Its Effect on the Bath in Slag Splashing

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Effect of Initial Microstructure on Impact Toughness of 1200 MPa-Class High Strength Steel with Ultrafine Elongated Grain Structure

A medium-carbon low-alloy steel was prepared with initial structures of either martensite or bainite. For both initial structures, warm caliber-rolling was conducted at 773 K (500 °C) to obtain ultrafine elongated grain (UFEG) structures with strong 〈110〉//rolling direction (RD) fiber deformation textures. The UFEG structures consisted of spheroidal cementite particles distributed uniformly in a ferrite matrix of a transverse grain size of about 331 and 311 nm in samples with initial martensite and bainite structures, respectively. For both initial structures, the UFEG materials had similar tensile properties, upper shelf energy (145 J), and ductile-to-brittle transition temperatures 98 K (500 °C). Obtaining the martensitic structure requires more rapid cooling than is needed to obtain the bainitic structure and this more rapid cooling promote cracking. As the UFEG structures obtained from initial martensitic and bainitic structures have almost identical properties, but obtaining the bainitic structure does not require a rapid cooling which promotes cracking suggests the use of a bainitic structure in obtaining UFEG structures should be examined further.     

Distribution and Accumulation of Neodymium and Its Effect on Secretion of Progesterone in Mice

Rareearthelementshavebeenincreasinglyusedinagriculture ,animalhusbandryandfisheryinChinasinceREcanpromotegrowthofcropsandani mals[1,2 ] .However ,studieshaveshownthatoverex posureofREmayhavenegativeortoxiceffectsonor ganisms ,forexample ,inhibitingenzymeactivityandinterferinginmetabolism ,havinghighaffinitytoCa2 bindingsitesanddown regulatingabsorptionandfunc tionofCa2 ,blockingbloodclotting ,inducingpatho histologicallesionsofliver ,aswellasaffectinggo nadalfunction[3～6 ] .Furthermore ,…     

Effect of Inhibitors on Corrosion of Gadolinium in Water

Effect of Inhibitors on Corrosion of Gadolinium in Water     

Tailoring the Processing Route to Optimize the Strength–Toughness Combination of Pearlitic Steel

Metallurgical and Materials Transactions A - The present study fine tunes the processing route of a eutectoid steel to shape an optimum strength–toughness combination through appropriate...     

Analysis of the Influence of Element’s Entropy on the Bulk Metallic Glass (BMG) Entropy,Complexity, and Strength

Metallurgical and Materials Transactions A - Bulk metallic glasses (BMGs) are disordered compounds without a long-range crystalline order. In this paper, we study the effect of an element’s...     

Toxicity of Lanthanum Against Rhizoctonia solani and Its Effect on Disease-Related Enzymes

Thoroughexperimentsandpracticeaboutrare earth(RE)elementshavebeenconductedsince 1970.ScientistsinChinahavesolvedaseriesofkey technologiesandappliedREelementssuccessfullyin agricultureproduction,andmadeChinabecomethe firstcountryapplyingREasacommercialprod…     

Effect of Rare Earths—Treated Glass Fiber on Impact Wear—Resistance of Metal—Plastic Multilayer Composites

The friction and wear properties under impact load and dry friction conditions of metal-plastic multilayer composites fillde with glass fiber,treated with rare earth elements,were investigated,The worn surfaces were observed and analyzed by scanning electron microscopy(SEM).It shows that applying rare earth elements surface modifier to treat the glass fiber surface can enhance the interfacial adhesion between the glass fiber and polytetrafluoroethylene (PTFE),as well as promote the interface properties of the composites,This helps to form a uniflrmly distributed and high adhesive trandfer film on the counterface and abate the friction between the composite and the counterface,As a result,the wear of compostite is greatly reduced.The composite exhibits execllent friciton properties and impact wear-resistance.     

Effect of Coiling Temperature on the Microstructure and Mechanical Properties of Hot-Rolled Ti–Nb Microalloyed Ultra High Strength Steel

A novel low carbon Ti–Nb microalloyed hot rolled steel with minimum yield strength of 700 MPa and good balance of stretch-flangeability and impact toughness has been developed by controlled thermo-mechanical processing following thin slab direct rolling route. In the present work, the effects of two coiling temperatures on the resulting microstructure, micro-texture and mechanical properties on this Ti–Nb microalloyed steel have been studied. It is observed that increase in coiling temperature from 520 to 580 °C significantly affects the mechanical properties. Higher dislocation density and increased precipitation along with slightly smaller grain size is observed for 580 °C coiling temperature resulting in about 50 MPa increase in yield and tensile strengths as compared to 520 °C coiling temperature.     

δ-Ferrite Formation and Its Effect on the Mechanical Properties of Heavy-Section AISI 316 Stainless Steel Casting

Metallurgical and Materials Transactions A - δ-Ferrite formation across the thickness of a heavy-section AISI 316 casting slab and the effect of its decomposition on the bending properties...     

Heat Treatment Design to Modify the Martensite Misorientation and Obtain Superior Strength–Toughness Combinations

Metallurgical and Materials Transactions A - A heat treatment methodology is described for obtaining ultra-high strength (>?1700 MPa) and increased...     

Pore Formation and Its Effect on Mechanical Properties in W—Ni—Fe Heavy Alloy

Abstract

W–Ni–Fe heavy alloy tensile specimens were sintered at 1450°C for various times up to 44h. The W content varied between 90 and 96 wt-%, and the Ni to Fe weight ratio was 1:1. The specimens are fully densified after 15 min to 1 h of sintering and show high strength and ductility. During the tension test, cracks are formed at the interface between tungsten grains when the grain deformation reaches critical levels. The number of these intergranular cracks increases with deformation until the specimens fracture. When the specimens are over-sintered for 4 and 8 h, large irregular pores are formed with a sharp decrease of strength and ductility. Upon further sintering, the porosity decreases again with a recovery of the mechanical properties. The results demonstrate that small amounts of porosity, even 1 or 2%, can cause drastic reduction of the mechanical properties in tungsten heavy alloys.     

Development of Silica Glass Coatings on 316L SS and Evaluation of its Corrosion Resistance Behavior in Ringer’s Solution

Sol-gel derived silica glasses have many promising features, including low-temperature preparation as well as chemical and physical stability. Two silica glasses with Si₁₀₀ and Si₈₀ composition were prepared to understand the factors contributing to the rate of bioactivity. The effects of pH, solution aging temperature, and molar ratio of H₂O/tetraethyl orthosilicate (TEOS) were studied, and the obtained powder sample was characterized by Fourier transform infrared spectroscopy, X-ray diffraction studies, and scanning electron microscopy. The synthesized silica glasses were deposited on 316L SS by the spin coating method at the optimized speed of 2000?revolutions per minute. The corrosion resistance behavior of the coatings was determined by (1) open-circuit potential vs time of exposure, (2) electrochemical impedance spectroscopy, and (3) cyclic polarization in Ringer??s solution. A higher breakdown potential (E _b) and repassivation potential (E _p) value with lower current density was obtained from cyclic polarization. Similar results were observed from impedance analysis with higher charge transfer resistance (R _ct) and lower double layer capacitance (C _dl) indicating the corrosion resistance behavior of the coatings compared with the uncoated 316L stainless steel. From the results, it was observed that both Si₁₀₀ and Si₈₀ glass coatings had a positive effect on the corrosion resistance behavior. An adhesive strength of 46?MPa and 45?MPa was obtained for the Si₁₀₀ and Si₈₀ coatings, respectively. An accelerated leach out study was carried out by impressing the potential at their breakdown potential to determine the effect of glass coating for long-term contact between the implant and a normal biological medium.     

Preparation and Structure Characterization of Rare Earth Doped Alumina-Siloxane Gel and Its Modification on ER Effect

A series of samples of alumina-siloxane gel wrapped by poly (methyl methacrylate) and doped with rare earths such as lanthanum, praseodymium, yttrium, gadolinium and europium were prepared. The structure features were characterized by micrograph, X-ray fluorescence spectrum, X-ray diffraction spectrum, Fourier transform infrared spectrum and differential thermal analysis.Tests indicate that rare earths modify the electrorheological effects of the stable suspensions composed of samples stirred with silicon oil.