CuZnAl Shape Memory Alloy Refined with Composite Rare Earths La Ce

TheCu-basedshapememoryalloys(SMA)havelowc0standrichresourcesandmayhavewidepracticalapplications,0wingtotheirbettershapememoryeffect(SME)thanNi-TiSMA.However,someseri0usproblemssuchasinter-granularfractureduetolargegrainsizeandsta-bilizati0nofmartensitemusthes0lvedbeforetheyareputinuse,Thewell-knownmethodforreducinggrainsizeistheadditionoflesssolub1e.l....t.[l'2j.Ithasbeenreportedthattherareearthelementshavedramaticeffectsinreducinggrainsizeandimprovingthemechanicalproper-tiessuchasbetterf…     

Thermo-mechanical Response and Damping Behavior of Shape Memory Alloy–MAX Phase Composites

NiTi/Ti₃SiC₂ interpenetrating composites that combine two unique material systems—a shape memory alloy (SMA) and a MAX phase—demonstrating two different pseudoelastic mechanisms, were processed using spark plasma sintering. The goal of mixing these two material systems was to enhance the damping behavior and thermo-mechanical response of the composite by combining two pseudoelastic mechanisms, i.e., reversible stress-induced martensitic transformation in SMA and reversible incipient kink band formation in MAX phase. Equal volume fractions of equiatomic NiTi and Ti₃SiC₂ were used. Microstructural characterization was conducted using scanning electron microscopy to study the distribution of NiTi, Ti₃SiC₂, and remnant porosity in the composite. Thermo-mechanical testing in the form of thermal cycles under constant stress levels was performed in order to characterize shape memory behavior and thereby introducing residual stresses in the composites. Evolution of two-way shape memory effect was studied and related to the presence of residual stresses in the composites. Damping behavior, implying the energy dissipation per loading–unloading cycle under increasing compressive stresses, of pure NiTi, pure Ti₃SiC₂, as-sintered, and thermo-mechanically cycled (TC) NiTi/Ti₃SiC₂ composites, was investigated and compared to the literature data. In this study, the highest energy dissipation was observed for the TC composite followed by the as-sintered (AS) composite, pure NiTi, and pure Ti₃SiC₂ when compared at the same applied stress levels. Both the AS and TC composites showed higher damping up to 200 MPa stress than any of the metal—MAX phase composites reported in the literature to date. The ability to enhance the performance of the composite by controlling the thermo-mechanical loading paths was further discussed.     

Phase Transformation Behaviors and Effects of Terbium in Polycrystalline Ni-Mn-Ga Magnetic Shape Memory Alloys

The phase transformation behaviors of two kinds of magnetic shape memory alloys NisoMn25 x Ga25-x and Ni50 Mn29Ga21-x Tbx were studied. When the composition of Ni in these alloys was constant, increasing Mn and reducing Ga contents make martensitic transformation temperatures rise obviously. Simultaneously, thermal hysteresis of phase transformation reduce but Curie temperature una|ters. When terbium was added, phase transformation temperature went up further and Curie temperature kept constant. The alloys still show strong ferromagnetism and properties of thermoelastic martensite phase transformation.     

Phase Equilibria and Phase Transition of the Ni–Fe–Ga Ferromagnetic Shape Memory Alloy System

Phase equilibria and martensitic and magnetic transitions of the β (B2 and L2₁) phase in the Ni–Fe–Ga system were investigated. The b phase was found to be in equilibrium with the γ (A1 structure) or γ′ (L1₂ structure) phase. The Curie temperature, T _c , equilibrium temperature, T _o 5 (Ms + Af)/2, martensitic transition starting temperature, M _s , and reverse transition finishing temperature, Af , of the β single–phase alloys were sensitive to the Fe and Ga compositions. The Fe substitution for Ni decreased and increased the T _o and T _c , respectively. The Ga substitution for Ni or Fe decreased both the T _o and T _c . The entropy change accompanying the reverse martensitic transition showed compositional dependence due to the magnetic contribution. The saturation magnetization I _s of the Ni–Fe–Ga system showed a strong dependence on the magnetic valence Z _M . The Is values of the Ni–Fe–Ga alloys annealed at 1023 K showed the same Z _m dependence as other ferromagnetic shape memory alloy (FSMA) systems. This article is based on a presentation made in the symposium entitled "Phase Transformations in Magnetic Materials," which occurred during the TMS Annual Meeting, March 12-16, 2006, in San Antonio, Texas, under the auspices of the Joint TMS–MPMD and ASMI–MSCTS Phase Transformations Committee.     

Crystal Structure of Ni50Mn29Ga21Tb1.2 Magnetic Shape Memory Alloy at Room Temperature

Preparation of Heteropoly Molybdoselenite Complex and Its Lanthanide Salts and Their Catalysis for Hydroxylation of Phenol     

Parsimonious prediction of Wechsler Memory Scale—III Memory Indices.

Equations for prorating the Wechsler Memory Scale—III Index scores were derived and validated on a sample of 252 mixed clinical cases. Regression equations were performed using age-scaled scores as predictors and the sum of age-scaled scores for Immediate Memory (IM) and General Memory (GM) as the criteria. Including Logical Memory and Verbal Paired Associates with either Faces or Family Pictures resulted in estimated scores that accounted for 95% to 97% of the variance for IM and GM. Over 80% of these cases had estimated sum of scaled scores that fell within 3 points of actual sum of scaled scores, within 1 standard error of measurement. When only Logical Memory and Verbal Paired Associates were included, estimations accounted for only 87% of the variance, and only 60% of the estimated scores fell within 3 points of actual sum of scaled scores. The regression equations are presented, as are the confidence intervals derived from a bootstrapping procedure that created 15,000 different samples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of Annealing Temperature and Time on Martensitic Transformation Temperatures and Mechanical Properties of the Ti–50.7 at % Ni Shape Memory Alloy

Russian Journal of Non-Ferrous Metals - The influence of temperature and time of recrystallization annealing on the characteristic temperatures of martensitic transformation and mechanical...     

Definition and Verification of Shape Meter Method

Ｓｈａｐｅｍａｔｈｅｍａｔｉｃａｌｍｏｄｅｌｆｏｒｍｅａｓｕｒｉｎｇａｎｄｃｏｎｔｒｏｌｌｉｎｇ ,ａｎａｌｙｔｉｃａｌｔｈｅｏｒｙｆｏｒｓｈａｐｅｓｔｉｆｆｎｅｓｓａｎｄｔｈｅｌａｗｏｆｃｏｏｒｄｉｎａｔｉｏｎｃｏｎｔｒｏｌｆｏｒｓｈａｐｅａｎｄｇａｕｇｅａｒｅｃａｌｌｅｄＳｈａｐｅＭｅｔｅｒＭｅｔｈｏｄ (ＳＭＭ ) .Ｔｈｅｓｔｕｄｙｏｆｓｈａｐｅｔｈｅｏｒｙａｎｄｔｅｃｈｎｏｌｏｇｙｈａｓｂｅｃｏｍｅｔｈｅｋｅｙｉｓｓｕｅｉｎｒｏｌｌｉｎｇｔｅｃｈｎｏｌｏｇｙｉｎｒｅｃｅｎｔ 4 0 ｙｅａｒｓ .Ｔ…     

Crystal Structure of Ni_(50)Mn_(29)Ga_(21)Tb_(1.2) Magnetic Shape Memory Alloy at Room Temperature

Crystal Structure of Ni_(50)Mn_(29)Ga_(21)Tb_(1.2) Magnetic Shape Memory Alloy at Room Temperature     

A Neural Network Recognition Method of Shape Pattern

The final objective of shape control is to makethe output shape data achieve the objective shapedata,then the adjusting magnitude of shape controlactuating mechanism can be defined in accordancewith the deflection value of the output shape dataand the objective shape data.In shape controlsystem,the first thing is to make shape faultpattern recognition based on the speciality andrequirement of shape control actuating mechanism ofrolling mill.The main assignment of shape patternrecognition is to…     

Quantitative Evaluation Method of Shape Indicator for Cold-rolled Strip

Quantitative level evaluation of cold-rolled strip was significant for the shape control and the product structure optimization. Based on the probability statistics method and the shape pattern recognition method, the shape evaluation model of cold-rolled strip was established to evaluate real-time shape of the online strip. The model was embedded in the shape control system, and the online strip shape state was real-time observed whether to meet the technical indicators, so the shape level could be identified and evaluated. Based on the shape evaluation indicators, the shape component could be well controlled to improve the shape hit rate and the control stability, so that the rolled strip shape could meet the technical requirements. At a 1050 cold strip mill, the shape data of the scene typical specifications strip were online collected and real-time evaluated, and the hit of macro shape in less than 8 I was 68.44%, indicating that the mill shape control had considerable room for improvement, as well as the evaluation method was feasible and practical for quantitative evaluation of the strip shape. So the new evaluation model has important guiding significance to increase value-added and reduce product quality objection.     

Roll Shape Setting Technology of Hot Galvanizing and Planishing Mill

 A roll shape setting model was built for the hot galvanizing and planishing mill. The uniform transversal distributions of the front tension in the exit and the unit pressure were considered as the objective function. At the same time, the quality of the products, the stability of zinc layer, and the homogeneity of spangles were of considerable significance in the planishing process. The model was applied to the roll shape setting of the 1800 cold rolling 3#CGL hot galvanizing and planishing mill of Baosteel Co Ltd. After being planished, the flatness of a strip that was less than 6 I was more than 97%, and the flatness of others were less than 10 I; the pass percentage of the zinc layers reached 100%.     

Near-Net Shape Continuous Casting of Aluminum Alloy Billet Using Electromagnetic Field

The present study investigates on the continuous casting of near-net shape aluminum billet using electromagnetic casting and stirring technology.Traditional machine for continuous casting process involves round,square and rectangular billets;therefore it requires additional multistep forging process to fabricate final products.A new process for the designed free-shaped billets offers some advantages:the process of extrusion and forging is simplified and the cost of plastic working can be greatly reduced.In order to reduce the peculiar problems such as surface crack and internal defect due to inhomogeneous heat transfer through solidified billets,electromagnetic casting and stirring technique were adopted.Through the numerical computer simulation,we have calculated the slit design of the free-shaped mold.The free-shaped aluminum billet was continuously cast at the various casting speed and coil current of about 1,200A.Breakout velocity and melt pool depth were measured.Surface and microstructure of the free-shape aluminum billet using EMC and EMS techniques were compared with those of the billet using the conventional DC casting.     

Theoretical and Experimental Study on Plug Shape Parameter of Press Piercing Mill

PPM ,theacronymofpresspiercingmill,hasbeenusedtoproducepiercedbilletfromcontinuoussquarebilletsince 1970s .The processcanreducecostandenergy ,andproducealloyedsteelpipe .Thistechnologyhasbeenwidelyadoptedinsomecompaniesrecently[1-3 ] .　　Becausethemetalflowisverycomplicateddur ingpresspiercing ,itisverydifficulttodeterminepiercingforceandplugshapewhichisrelatedtode formation .Ref [4 ]hascomparedtheplugswithdifferentshapesandpointedoutthatiftheplugconehasasharpangle ,thepiercingforcecanberedu…     

Participating in Global Pricing:“Shanghai Price”Comes into Shape

Shanghai Copper Market has become an impor-tant link of the international copper marketprice chain:along with London and New York,Shanghai is ranked as one of the three globalcopper pricing centers.In the domestic coppermarket,people wait and see the opening quota-tions of Shanghai Copper Market every day to     

Influence of DogBone Apex on Shape During Slab Horizontal Rolling Process

The deformation of slab with dogbone shape during the horizontal rolling process was simulated using FEM, and the influences of apical dislocation of dogbone on the slab spread as well as the minimum crop end loss and the lost width at slab head and tail were analyzed. The results show that with the increase in the apical dislocation of dogbone (LA), the slab spread and the minimum crop end loss at slab head and tail decrease, while the lost width at slab head and tail increases. Meanwhile, the relationships of S/LALA, LH/LALA, WH/LALA, LT/LALA, and WT/LALA were obtained.     

Velocity Preset and Transitional Zone′s Shape Optimization for Tailor Rolled Blank

Tailor rolled blank(TRB)is a type of emerging material to produce lightweight vehicle parts.Transitional zone′s shape is an important parameter for tailor rolled blank.It not only affects mold design and the local carrying capacity of the stamping parts,but also determines the maximum value and variation characteristics of rolling force.How to get the best transitional zone′s shape is a key problem for production of tailor rolled blank.A double power function is put forward using for transitional curve,which is continuous and smooth at all connection points independent of its parameters,so the sudden change of mechanical parameters during rolling and forming process can be avoided.At the same time,the velocity formula and restriction for arbitrary transitional curve are derived to preset vertical velocity of the roller and judge whether the curve can be rolled successfully or not.Then,the finite element method(FEM)is used to verify the precision of velocity formula and study the mechanical characteristics of different curves.Finally,a method to obtain the optimal curve equation is put forward and verified.     

Coupled Densification—Shape Distortion Analysis of Liquid Phase Sintering Affected By Gravity

The paper presents a model of nonlinear viscous behavior in the examination of gravity-induced distortion during liquid phase sintering. The model uses a finite element formulation to describe densification, viscous flow, and the associated dimensional changes and component slumping during sintering. The approach assumes sintering is conducted under isothermal conditions with averaged material properties. The numerical results are compared with experimental data and with a mathematical model on the distortion during liquid phase sintering of tungsten heavy alloys. The preliminary conclusions aim to provide better understanding of dimensional control during liquid phase sintering.