{"title":"A Study of the Quench Sensitivity of 6061-T6 and 6069-T6 Aluminum Alloys","authors":"M. E. Kassner, P. Geantil, X. Li","doi":"10.1155/2011/747198","DOIUrl":"https://doi.org/10.1155/2011/747198","url":null,"abstract":"The purpose of this study is to investigate the quench sensitivity of the mechanical properties of 6061 and 6069 aluminum alloys. The relationship between mechanical properties and quench delay time at various temperatures between 200–500°C was determined. It was concluded that the 6069-T6 was somewhat more quench sensitive than 6061, which may be consistent with the composition difference. This study also provides increased data on the quench sensitivity of the traditional alloy, 6061-T6.","PeriodicalId":16342,"journal":{"name":"Journal of Metallurgy","volume":"10 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2011-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85203662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Theoretical Study of a Thermophysical Property of Molten Semiconductors","authors":"Fathi Aqra, A. Ayyad","doi":"10.1155/2011/436704","DOIUrl":"https://doi.org/10.1155/2011/436704","url":null,"abstract":"This paper deals with theoretical approach to surface tension of molten silicon and germanium, and contributes to this field, which is very important. A theoretical calculation for determining the surface tension of high-temperature semiconductor melts, such as molten silicon and germanium, in the temperature range 1687–1825 K and 1211–1400 K, respectively, is described. The calculated temperature-dependence surface tension data for both Si and Ge are expressed as 𝛾=876−0.32(𝑇−𝑇𝑚) and 𝛾=571−0.074(𝑇−𝑇𝑚) (mJ m−2), respectively. These values are in consistence with the reported experimental data (720–875 for Si and 560–632 mJ m−2 for Ge). The calculated surface tension for both elements decreases linearly with temperature.","PeriodicalId":16342,"journal":{"name":"Journal of Metallurgy","volume":"10 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2011-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86861600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"One-Dimensional Constitutive Model of Shape Memory Alloy with an Empirical Kinetics Equation","authors":"Lei Li, Qingbin Li, Fan Zhang","doi":"10.1155/2011/563413","DOIUrl":"https://doi.org/10.1155/2011/563413","url":null,"abstract":"Characteristics of NiTi shape memory alloy (SMA) and its constitutive model with an empirical kinetics equation were investigated in this paper. Firstly, the transformation characters of the NiTi SMA were obtained through a differential scanning calorimetry (DSC) analysis technology, and the properties during incomplete and discontinuous transformation process and the effects of plastic deformation on the transformation were studied. The uniaxial tension, SME, and constrained recovery process of NiTi SMA were examined through an improved 10KN universal material testing machine. Experimental results indicated that the phase transformation characters and the mechanical properties could be affected by the loading process considerably, and the plastic deformation should be taken into account. To simulate the characteristics of NiTi SMA more effectively, a one-dimensional constitutive model derived from the internal variable approach with the consideration of the plastic deformation was constructed based on the DSC and the uniaxial tension experimental results, and a new simple empirical kinetics equation was presented, with the transformation temperature parameters redefined according to the DSC experiment evidence. Comparison between the numerical and experimental results indicated that this constitutive model could simulate the phase transformation characters, the uniaxial tension, SME, and the constrained recovery behavior of NiTi SMA well.","PeriodicalId":16342,"journal":{"name":"Journal of Metallurgy","volume":"4 1","pages":"1-14"},"PeriodicalIF":0.0,"publicationDate":"2011-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80808062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Namazu, M. Komatsubara, H. Nagasawa, T. Miki, T. Tsurui, S. Inoue
{"title":"Titanium-Nickel Shape Memory Alloy Spring Actuator for Forward-Looking Active Catheter","authors":"T. Namazu, M. Komatsubara, H. Nagasawa, T. Miki, T. Tsurui, S. Inoue","doi":"10.1155/2011/685429","DOIUrl":"https://doi.org/10.1155/2011/685429","url":null,"abstract":"The fabrication and characterization of forward-looking active catheter actuated by titanium-nickel (Ti-Ni) shape memory alloy (SMA) springs are described. The catheter has been designed for wide-range observation of an affected area inside a blood vessel when the blood vessel is occluded. The developed active catheter consists of eight Ti-Ni SMA spring actuators for actuation of catheter tip, an ultrasonic transducer for forward-looking, a guide wire, a polyurethane tube for coating, and spiral wirings for realization of various flexure motions of catheter tip using Ti-Ni SMA actuators. The size of the catheter is 3.5 mm in diameter and 60 mm in length of the sum of transducer and actuator sections. Ti-Ni SMA springs were fabricated from a Ti-50.9at.%Ni sheet by electrochemical etching with a mixed solution of ethanol and lithium chloride. The catheter was assembled by hand under a stereomicroscope. The tip of the produced catheter was able to move in parallel toward at least eight directions by controlling an applied current to Ti-Ni SMA springs. We have confirmed that the active catheter was able to observe an object settled in the front.","PeriodicalId":16342,"journal":{"name":"Journal of Metallurgy","volume":"105 3 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2011-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83220775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Amorphization, Crystallization, and Magnetic Properties of Melt-Spun Alloys","authors":"Liya Li, W. Xie","doi":"10.1155/2011/910268","DOIUrl":"https://doi.org/10.1155/2011/910268","url":null,"abstract":"Effects of Cr3C2 content and wheel surface speed on the amorphous formation ability and magnetic properties have been investigated for melt-spun () alloys. Ribbon melt-spun at lower wheel speed (30 m/s) has composite structure composed of mostly SmCo7, a small amount of Sm2Co17, and residual amorphous phases. The grain size of SmCo7 phase decreases with the increase of Cr3C2 content . When melt spinning at 40 m/s, alloys can be obtained in the amorphous state for with intrinsic coercive of the order of 40–70 Oe. DSC analysis reveals that SmCo7 phase first precipitates from the amorphous matrix at 650∘C, followed by the crystallization of Sm2Co17 phase at 770∘C. Optimal coercivity of 7.98 kOe and remanent magnetization of 55.05 emu/g have been realized in magnet subjected to melt spinning at 40 m/s and annealing at 650∘C for 5 min. The domain structure of the annealed ribbon is composed of interaction domains typically 100–400 nm in size, which indicates the presence of a strong exchange coupling between the grains.","PeriodicalId":16342,"journal":{"name":"Journal of Metallurgy","volume":"42 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2011-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89842955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Process Heating and Postannealing Effects on Microstructure and Hardness of the Sputtered Ni-P-Al Coatings","authors":"Yu-Ming Su, Chia-Che Wu, F. Wu","doi":"10.1155/2011/802093","DOIUrl":"https://doi.org/10.1155/2011/802093","url":null,"abstract":"Ternary Ni-P-Al alloy coating was fabricated by magnetron sputtering technique with a Ni-P/Al composite target source. The effects of thermal treatments, including deposition process heating and postannealing, on phase transformation phenomenon and related mechanical properties were investigated. The as-deposited coatings produced under process temperature below 475∘C showed an amorphous/nanocrystalline microstructure. Significant crystallization of Ni matrix and precipitation of Ni𝑥P𝑦 and Ni𝑝Al𝑞 compounds were observed for the coatings manufactured under high sputtering temperatures above 500∘C. The amorphous Ni-P-Al coatings were postannealed from 500 to 600∘C in vacuum environment for comparison. The amorphous feature of the Ni-P-Al coating remained unchanged under a high annealing temperature of 550∘C, showing a superior thermal stability as compared to those fabricated under high process temperatures. Superior hardness was obtained for the post-annealed Ni-P-Al coatings due to volumetric constraint of crystallization and precipitation. On the other hand, the overaging phenomenon and subsequent degradation in hardness were found for the Ni-P-Al coatings fabricated under high-temperature deposition processes. The phase transformation mechanisms of the coatings through different thermal treatments were intensively discussed.","PeriodicalId":16342,"journal":{"name":"Journal of Metallurgy","volume":"19 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2011-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90344196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tracer Diffusion Mechanism in Amorphous Solids","authors":"P. K. Hung, P. H. Kien, H. V. Hue","doi":"10.1155/2011/861373","DOIUrl":"https://doi.org/10.1155/2011/861373","url":null,"abstract":"Tracer diffusion in amorphous solid is studied by mean of -bubble statistic. The -bubble is defined as a group of atoms around a spherical void and large bubble that represents a structural defect which could be eliminated under thermal annealing. It was found that amorphous alloys such as (, 81.5 and 70) and suffer from a large number of vacancy bubbles which function like diffusion vehicle. The concentration of vacancy bubble weakly depends on temperature, but essentially on the relaxation degree of considered sample. The diffusion coefficient estimated for proposed mechanism via vacancy bubbles is in a reasonable agreement with experiment for actual amorphous alloys. The relaxation effect for tracer diffusion in amorphous alloys is interpreted by the elimination of vacancy bubbles under thermal annealing.","PeriodicalId":16342,"journal":{"name":"Journal of Metallurgy","volume":"68 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75249271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Dislocation-Based Theory for the Deformation Hardening Behavior of DP Steels: Impact of Martensite Content and Ferrite Grain Size","authors":"Y. Bergström, Y. Granbom, D. Sterkenburg","doi":"10.1155/2010/647198","DOIUrl":"https://doi.org/10.1155/2010/647198","url":null,"abstract":"A dislocation model, accurately describing the uniaxial plastic stress-strain behavior of dual phase (DP) steels, is proposed and the impact of martensite content and ferrite grain size in four com ...","PeriodicalId":16342,"journal":{"name":"Journal of Metallurgy","volume":"10 1","pages":"1-16"},"PeriodicalIF":0.0,"publicationDate":"2010-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83292562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Temperature Control in Spark Plasma Sintering: An FEM Approach","authors":"G. Molénat, L. Durand, J. Galy, A. Couret","doi":"10.1155/2010/145431","DOIUrl":"https://doi.org/10.1155/2010/145431","url":null,"abstract":"Powder consolidation assisted by pulsed current and uniaxial pressure, namely, Spark Plasma Sintering (SPS), is increasingly popular. One limitation however lies in the difficulty of controlling the sample temperature during compaction. The aim of this work is to present a computational method for the assembly temperature based on the finite elements method (FEM). Computed temperatures have been compared with experimental data for three different dies filled with three materials with different electrical conductivities (TiAl, SiC, Al2O3). The results obtained are encouraging: the difference between computed and experimental values is less than 5%. This allows thinking about this FEM approach as a predictive tool for selecting the right control temperatures in the SPS machine.","PeriodicalId":16342,"journal":{"name":"Journal of Metallurgy","volume":"5 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2010-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76415687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Thermodynamic Studies of the Arsenic Adsorption on Iron Species Generated by Electrocoagulation","authors":"J. Parga, V. Vazquez, H. Moreno","doi":"10.1155/2009/286971","DOIUrl":"https://doi.org/10.1155/2009/286971","url":null,"abstract":"Protection of global environment and sustainable sources of clean water are a necessity for human survival. The wide use of heavy metals by modern industries has generated heavy metals containing wastes and by-products. Specifically, large quantities of arsenic compounds are being discharged into the environment. The full potential of Electrocoagulation (EC) with air injection as an alternative wastewater treatment technique to remove arsenic from water showed more than 99 percent of removal without adding any chemicals. This study has been carried out to determine the feasibility of arsenic adsorption on iron species by EC process using the Langmuir's Isotherm. Thermodynamic parameters such as , , and were calculated. It was found that the adsorption process is exothermic and spontaneous. Some experiments were conducted to determine the optimum operating conditions such as current density, pH, and residence time. Also in this study, X-Ray Diffraction, Scanning Electron Microscopy, Mossbauer Spectroscopy, and Fourier Transform infrared spectroscopy were used to characterize the EC solid products that revealed the expected crystalline iron oxides (lepidocrocite, magnetite, gohetite, and iron oxide).","PeriodicalId":16342,"journal":{"name":"Journal of Metallurgy","volume":"2 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2009-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81583379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}