550 Matching Results

Search Results

Advanced search parameters have been applied.

Materials Handbook : Part III - Low Tin Zirconium Alloys

Description: "These notes are intended to serve as a summary of the current knowledge of properties of materials. In the future some need may exist for related information of methods of testing, design and fabrication. This issue presents information on low tin-zirconium alloys with subdivision..."
Date: January 29, 1953
Creator: Majors, Harry, (Jr.); Webster, R. T.; Wendell, G. E. & Wallace, R. H.
Partner: UNT Libraries Government Documents Department

Single Bend Tests on Welded Zirconium and Zirconium-Tin Alloys

Description: Introduction: "Since it has been found that zirconium and zirconium-tin alloys may be embrittled by certain heat treatments, it was decided to determine if welding of these materials affects their ductility in any way. A single bend test in both the longitudinal and transverse directions was used for evaluation of the variables considered."
Date: June 4, 1952
Creator: Hoge, H. R.
Partner: UNT Libraries Government Documents Department

Mechanical Properties of Zirconium-Tin Alloys

Description: Abstract: "The mechanical properties and corrosion resistance of induction-melted, zirconium-tin alloys have been determined. The alloys investigated contained from zero to five per cent tin and up to 0.3% carbon. The zirconium used was United States Bureau of Mines sponge zirconium. The mechanical properties investigated include the tensile, hot-hardness, and impact properties."
Date: December 22, 1952
Creator: Schwope, A. D. & Chubb, Walston
Partner: UNT Libraries Government Documents Department

Transport and Magnetization Properties of rolled RRP Nb3Sn Strands.

Description: Restack Rod Process (RRP) strands with 54 and 108 sub-elements were rolled from 0.7 mm diameter to 0.45 mm thickness to simulate the deformation of strands at the edges of Rutherford cables. Various diagnoses were then applied to assess performance and stability. Transport measurements were used to assess the effect of rolling on the critical current. Magnetization measurements were used to probe superconducting pathway bridging between deformed sub-elements. The copper residual resistivity ratio RRR was also measured to assess tin contamination due to thinned or ruptured diffusion barriers. While systematic changes were observed in all three measurements with increasing deformation, RRR showed the strongest changes. The implications of these measurements for cable stability, and their relationship to observations of the strand cross-section by light microscopy, are discussed.
Date: August 27, 2007
Creator: Ghosh,A.K.; Cooley, L.D.; Dietderich, D.R. & Sun, L.
Partner: UNT Libraries Government Documents Department

Solderability Study of Tin/Lead Alloy Under Steam-Aging Treatment by Electrochemical Reduction Analysis and Wetting Balance Tests

Description: Two types of solder samples, pins and through-holes were tested by SERA™ (Sequential Electrochemical Reduction Analysis) and Wetting Balance after various length of steamaging treatment. It was shown that after steam-aging, both types of specimen gave a similar electrochemical reduction curve, and solderabilty predictions made from SERA™ test agree with results obtained from Wetting Balance test on a qualitative base. Wetting balance test of pin samples after SERA™ test confirmed that SERA™ is a non-destructive testing method -- it even restored solderability. Comparison of electrochemical reduction behavior of samples under different treatment indicates that steam-aging can not reproduce exactly the effect of naturally atmospheric aging, and may not be the best artificial accelerating environment adopted.
Date: May 1993
Creator: Gao, Yang, 1966-
Partner: UNT Libraries

Structure and properties of metal hydrides prepared by mechanical alloying

Description: Our research examines the structure and reversible hydrogen storage capacity of alloys based on the LaNi{sub 5} intermetallic. The alloys are prepared by mechanical alloying (MA), a technique particularly useful when alloying LaNi{sub 5} with low melting point elements such as tin and calcium. In LaNi{sub 5-y}Sn{sub y}, x-ray diffraction and Rietveld analysis show that tin preferentially occupies the Ni(3g) sites in the LaNi{sub 5} structure, and the unit cell volume increases linearly with tin content to a maximum tin solubility of 7.33 atomic percent (LaNi{sub 4.56}Sn{sub 0.44}). The addition of tin to LaNi{sub 5} causes (a) a logarithmic decrease in the plateau pressures for hydrogen absorption and desorption, which is consistent with the corresponding increase in the volume of the LaNi{sub 5} unit cell; (b) a decrease in the hysteresis between the pressures for hydride formation and decomposition, which is in agreement with a recent theoretical model for the effect; and (c) a linear decrease in the hydrogen storage capacity. Effect (c) is explained by a rigid-band model whereby electrons donated by the tin atoms occupy holes in the 3d band of LaNi{sub 5}, which could otherwise be occupied by electrons donated by the hydrogen atoms. Thermodynamic van`t Hoff analysis for these alloys show an increase in hydride formation enthalpy and no change in entropy with increasing tin concentration. LaNi{sub 5} with calcium additions shows enhanced kinetics of hydrogen absorption/desorption. The powder particles prepared by MA have a larger surface area than particles of the same overall size prepared by arc casting. All LaNi{sub 5}-based alloys prepared by MA in an inert environment require no activation for hydrogen absorption and suffer less comminution upon hydriding/dehydriding.
Date: September 1, 1995
Creator: Wasz, M.L. & Schwarz, R.B.
Partner: UNT Libraries Government Documents Department

Effects of temperature ramp rate during heat treatment on hysteresis loss and critical current density of internal tin processed wires

Description: It has been shown that temperature ramp rates utilized in heat treatment schedules for internal tin processed Nb{sub 3}Sn wires substantially influence both hysteresis loss and critical current density J{sub c} of the wires, i.e. a slow ramp rate (e.g. 6{degree}C/h) favors a higher J{sub c} while a fast ramp (e.g. 60{degree}C/h)results in a low hysteresis loss of the wire.
Date: April 1, 1995
Creator: Suenaga, M. & Sabatini, R.L.
Partner: UNT Libraries Government Documents Department

Modeling non-isothermal intermetallic layer growth in the 63Sn-37Pb/Cu system

Description: A model describing diffusion-controlled growth of multiple intermetallic layers and the displacement of the interfaces between layers was developed and implemented in a 1-D computer code based on method-of-lines. The code was applied to analysis of intermetallic layer growth in isothermal solder aging experiments performed with 100 Sn/Cu and 63Sn-37Pb/Cu solder-substrate systems. Analyses indicated that intermetallic layer growth was consistent with a bulk diffusion mechanism involving Cu and/or Sn. In this work, nonisothermal solder-aging experiments were done with the 63Sn- 37Pb/Cu system using two temperature histories (4 cycles/day between 223-443 K, and 72 cycles/day between 223-443 K). Isothermal experiments were also done at 443 K. Thickness of Cu{sub 3}Sn and Cu{sub 6}Sn{sub 5} intermetallic layers were determined vs time for each temperature history. An updated version of the model and code were used to predict the intermetallic layer growth. Arrhenius expressions for diffusion coefficients in both Cu3Sn and Cu6Sn5 layers were determined. Agreement between prediction and experiment was generally good. In some cases, predicted layer growth was less than experiment, but within error. This paper describes the nonisothermal experiments and a comparison of predicted and observed layer growth vs time.
Date: December 31, 1996
Creator: Vianco, P.T.; Hopkins, P.L.; Erickson, K.L.; Frear, D.R. & Davidson, R.
Partner: UNT Libraries Government Documents Department

Microstructural changes in eutectic tin-lead alloy due to severe bending

Description: Severe plastic deformation in an eutectic tin-lead alloy is studied by imposing fast bending at room temperature, in an attempt to examine the microstructural response in the absence of thermally activated diffusion processes. A change in microstructure due to this purely mechanically imposed load is observed: the tin-rich matrix phase appears to be extruded out of the narrow region between neighboring layers of the lead-rich phase and alterations in the colony structure occur. A micromechanism is proposed to rationalize the experimental observations.
Date: February 29, 2000
Creator: SHEN,Y.-L.; ABEYTA,M.C. & FANG,HUEI ELIOT
Partner: UNT Libraries Government Documents Department

Magnetic designs and field quality of Nb{sub 3}Sn accelerator magnets

Description: This paper presents a new approach to accelerator magnet design, based on simple and robust single-layer coils with minimum number of turns arranged horizontally or vertically in a common iron yoke. Cos-theta and block type coil geometries as well as cold and warm iron yoke designs were studied. Coils and yokes were optimized for the maximum field, minimum field harmonics, and minimum sizes.
Date: January 14, 2002
Creator: Kashikhin, Vadim V. & Zlobin, Alexander V.
Partner: UNT Libraries Government Documents Department

Development of cos-theta Nb{sub 3}Sn dipole magnets for VLHC

Description: This paper describes the double aperture dipole magnets developed for a VLHC based on Nb{sub 3}Sn superconductor, a cos-theta coil, cold and warm iron yokes, and the wind-and-react fabrication technique. Status of the model R and D program, strand and cable and other major component development are also discussed.
Date: July 20, 2001
Creator: al., Alexander Zlobin et
Partner: UNT Libraries Government Documents Department

Magnetism in single-crystalline CePtSn.

Description: CePtSn exhibits two antiferromagnetic transitions at low temperatures. We report on magnetoresistance and in magnetization studies of single-crystalline CePtSn in magnetic fields up to 18 T. The data were taken to establish the magnetic phase diagrams for CePtSn in fields applied along the principal directions.
Date: August 4, 1999
Creator: Bordallo, H. N.; Chang, S.; Lacerda, A. H.; Nakotte, H.; Takabatake, T. & Torikachvili, M. S.
Partner: UNT Libraries Government Documents Department

High-field magnetization studies of U{sub 2}T{sub 2}Sn (T=Co, Ir, Pt) compounds

Description: High-field magnetization measurements at 4.2 K on U{sub 2}T{sub 2}Sn (T = Co, Ir and Pt) compounds have been performed on free and fixed powders up to 57 T. An antiferromagnetic ground state of U{sub 2}Pt{sub 2}Sn is corroborated by a metamagnetic transition at 22 T with very small hysteresis going up and down with field. U{sub 2}Co{sub 2}Sn and U{sub 2}Ir{sub 2}Sn show no metamagnetic transition up to 57 T which is in agreement with the non-magnetic ground state of these compounds. In all cases, the maximum applied field is not sufficient to achieve saturation. The short-pulse measurements presented here are compared with previous results obtained in quasi-static fields up to 35 T.
Date: July 1, 1995
Creator: Prokes, K.; Nakotte, H. & de Boer, F.R.
Partner: UNT Libraries Government Documents Department

Characterization of superconductors with artificial pinning microstructures

Description: Extension of the APC approach to Nb{sub 3}Sn requires that a second phase be introduced into the Nb{sub 3}S reaction layer with the intent of increasing the volume pinning strength. This can be achieved by either the refinement of the Nb{sub 3}S grains due to the presence of a second phase or by the second phase itself pinning flux. If a bronze-type process is to be used a different addition than Zr is required since internal oxidation of Nb is not possible. The criteria for elements to be candidates for the APC approach are discussed. The results for one of the candidates (Ag) show that it is not incorporated into the Nb{sub 3}S, however, its addition did increase the growth rate.
Date: October 1, 1994
Creator: Dietderich, D.R. & Scanlan, R.M.
Partner: UNT Libraries Government Documents Department