Alcan

About: Alcan is a based out in . It is known for research contribution in the topics: Aluminium & Alloy. The organization has 2684 authors who have published 2661 publications receiving 41798 citations. The organization is also known as: Rio Tinto Alcan.

The formation of controlled-porosity membranes from anodically oxidized aluminium

Abstract: Synthetic membranes are used in a number of diverse applications, such as filtration1,2, bioreactors2,3, tissue culture4, analytical devices including sensors2,5, and as supports for active materials1,5. Narrow pore-size distribution, high pore density and thinness are often important attributes. The anodic oxidation of aluminium6 can produce porous films possessing these features; the anodizing voltage controls the pore size and pore density, whereas the thick-ness is determined by the amount of charge transferred. A major problem with this technique, however, is that the films remain attached to the aluminium, with the pore base closed by an oxide barrier layer. Here we overcome this problem by progressively reducing the anodizing voltage, thereby causing perforation of the barrier layer and separation of the film as a porous membrane.

Aspects of fracture in particulate reinforced metal matrix composites

Abstract: The tensile deformation and fracture behaviour of the aluminium alloy 6061 reinforced with SiC has been investigated. In the T4 temper plastic deformation occurs throughout the gauge length and the extent of SiC particle cracking increases with increasing strain. In the T6 temper strain becomes localised and particle cracking is more concentrated close to the fracture. The elastic modulus decreases with increasing particle damage and this allows a damage parameter to be identified. The fraction of SiC particles which fracture is less than 5%, and over most of the strain range the damage controlling the tensile ductility can be recovered, indicating that other factors, in addition to particle cracking are important in influencing tensile ductility. It is suggested that macroscopic fracture is initiated by the SiC particle clusters that are present in these composites as a result of the processing. The matrix within the clusters is subjected to high levels of triaxial stress due to elastic misfit and the constraints exerted on the matrix by the surrounding particles. Final fracture is then produced by crack propagation through the matrix between the clusters.

Environmental Life Cycle Costing

Abstract: A Dialog, over Coffee, about Life Cycle Costing Executive Summary Three Categories of Life Cycle Costing System Boundaries in Environmental Life Cycle Costing Example Calculations in Environmental Life Cycle Costing History of Life Cycle Costing, Its Categorization, and Its Basic Framework, K. Lichtenvort, G. Rebitzer, G. Huppes, A. Ciroth, S. Seuring, W.P. Schmidt, E. Gunther, H. Hoppe, T. Swarr, and D. Hunkeler History and Development of Conventional LCC Types of LCC Two Key Limitations of LCC to Be Tackled by Environmental LCC The Requirement and General Framework for Environmental Life Cycle Costing Modelling for Life Cycle Costing, G. Huppes, A. Ciroth, K. Lichtenvort, G. Rebitzer, W.-P. Schmidt, and S. Seuring Introduction Cost Models Cost Categories Cost Bearers Uncertainties and Inconsistencies in Cost Data Cost Aggregation Environmental LCC, G. Rebitzer and S. Nakamura Objectives of Environmental LCC System Boundaries and Scope Calculating Life Cycle Costs based on the Process LCI of LCA Environmental LCC in Relationto Conventional and Societal LCC Calculating Life Cycle Costs Based on Hybrid LCA Integrating External Effects into LCC, B. Steen, H. Hoppe, D. Hunkeler, K. Lichtenvort, W.-P. Schmidt, and E. Spindler Introduction Definition, Identification, and Categorization of Externalities Monetization Internalizing Externalities LCC in Life Cycle Management, T. Swarr and D. Hunkeler Corporate Perspective Integrating LCC into Management Continuous Product Improvement A Survey of Current LCC Studies, A. Ciroth, K. Verghese, and C. Trescher Intention Relation of This Chapter to the Other Chapters Parameters and Settings of LCC Studies in Practice Sampling Procedure of Studies for the Survey Summary of Results Outlook: Toward an LCC Case Study Library Analysis of the Survey's Results Conclusions and Questions Life Cycle Costing Case Studies, A. Ciroth, C.-O. Gensch, E. Gunther, H. Hoppe, D. Hunkeler, G. Huppes, K. Lichtenvort, K. Ludvig, B. Notarnicola, A. Pelzeter, M.Prox, G. Rebitzer, I. Rudenauer, and K. Verghese Introduction Organic versus Conventional Extra-Virgin Olive Oil Waste Water Treatment Light Bulb: Comparison of Energy-Saving and Incandescent Lamps Double-Deck Carriage Floor (BAHNKREIS Project) Washing Machine Hypothetical Case: A High-Capacity Glass Cable Network for Data Transmission Passenger Car Life Cycle Costs of Real Estate Conclusions Three Types of Life Cycle Costing Temporal Aspects and Discounting of LCC Results Learnings from Applied LCC Carried Out to Date State of the Art and Rules of Thumb in Carrying Out Life Cycle Costing Role of Environmental Life Cycle Costing in Sustainability Assessment, W. Klopffer Sustainability Discussion Appendices Appendix to Case Study Boxes Appendix to Chapter 4: Social Impacts Appendix to Chapter 6: Survey Form Glossary References Index

Precipitation hardening in Al–Mg–Si alloys with and without excess Si

Abstract: The aluminum alloys of the 6xxx series contain an excess of Si above that required to form stoichiometric Mg 2 Si, which is added to improve the age hardening due mostly to precipitation of metastable β″ precipitates. The excess Si is not believed to alter the precipitation sequence, structure and lattice parameters of the different metastable precursors, but rather promotes formation of additional particles/phases which do not contribute to hardening significantly. The presence of excess Si changes the composition and density of metastable β″ particles, although a systematic study of the Mg/Si ratio in particles from alloys of different composition is lacking. In this paper, it is shown that the precipitation sequence in the balanced alloy is independent of the composition and the strength increases with Mg 2 Si level. This is due primarily to both a higher volume fraction and a refined distribution of the β″ particles. Excess Si increases the effective amount of the hardening phases above ∼0.9 wt.% Si. It modifies the Mg/Si ratio in the clusters/zones and β″ precipitates and improves strength by altering their size, number density and distribution. In addition, the extent and rate of strengthening increases until the overall Mg to Si ratio in the alloy is close to approximately 0.4. The hardening precipitates with reduced Mg to Si ratio become less stable with aging and cause a decrease in strength during over aging.