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By Kurt D. Mitchell

"This paper discusses general application for A C variable frequency drives in the mining industry. A review of induction motors characteristics, adjustable frequency controller fundamentals, and three commonly used controllers is presented. General application guidelines for the three different types of controllers; variable voltage input , current source input and pulse width modulated are then reviewed in detail, and an example of the economic benefit of this technology is discussed. IntroductionSoon after static DC variable speed drives were well established in industry, a need for static AC variable speed drives was seen. The first technical papers describing possible systems appeared in the mid-1960s, with commercially available units arriving in the early 1970s. Without exception, static AC drives are substantially more complex than their DC counterparts, but they have some very desirable properties. As compared to DC motors, AC motors are less costly, physically smaller, more reliable, require less maintenance , easily sealed, have good load regulation, are able to run at higher operating voltages, and have little danger of over-speed runaway . These properties are particularly desirable in explosion-proof, submersible or difficult accessibility applications.Variable speed AC drives are now a proven technology. available in packages from Sub-horsepower to hundreds of horsepower, from 115VAC to 4160 VAC. This paper covers the principles of operation of three common types of controllers, application criteria, motor consideration and finally an example of how an AC variable speed drive can pay for itself in terms of energy savings."

Jan 1, 1986

By D Martín, G. Díaz, F. Cubeddu, A. B. Mejias

The Modified ZINCEXTM Process (MZP), developed by Técnicas Reunidas, is an industrially proven flexible process. It can handle a wide range of primary and secondary raw materials, producing SHG zinc. The core of the Modified ZINCEXTM Process is the zinc solvent extraction unit. This unit is an effective barrier for any leachable impurities present in the raw material. As a result of this an ultra-pure zinc solution is always obtained. The high versatility of the process makes the application of the technology in different scenarios possible. MZP can be effectively applied when developing a whole new plant (Skorpion) or adapting its scheme to an existing refinery (Akita), in both cases giving the same results. Flexibility in terms of capacity of the plant is a great advantage of the MZP, there is the possibility to adapt the global process to a wide range of production capacities. Zinc production capacities of over 150 000 t/a may be achieved with a single solvent extraction plant train. The robustness of the Modified ZINCEXTM Process has been recently proven on two new plants currently in operation: Portovesme (Italy) and Horsehead (USA) after start up during 2013. The status of both plants is described in this paper.

Jan 1, 2014

By S. D. Normani

A Deep Geologic Repository (DGR) for Low and Intermediate Level radioactive waste has been proposed by Ontario Power Generation for the Bruce Nuclear site in Ontario, Canada. The DGR is to be constructed at a depth of about 680m below ground surface within the argillaceous Ordovician limestone of the Cobourg Formation. The objective of this paper is to apply paleoclimate boundary conditions to a regional-scale groundwater flow model for the DGR site and to describe the influence of glacial loading and unloading on flow system evolution using the FRAC3DVS-OPG flow and transport model. The regional-scale domain encompasses an area of 18,775km2 extending from Lake Huron to Georgian Bay in southwestern Ontario, Canada. From a hydrogeologic perspective, the domain can be subdivided into a shallow zone, an intermediate zone, and a deep zone comprised of the low-permeability units of Ordovician and the more permeable Cambrian where present. The deep groundwater zone is characterized by units containing stagnant water having high concentrations of total dissolved solids (TDS) that can exceed 300g=L. The high TDS values at depth require density-dependent coupled flow and transport calculations within FRAC3DVS-OPG. The computational sequence involves the calculation of steady-state density independent flow that is used as the initial condition for the determination of pseudo-equilibrium for a density-dependent flow system that has an initial TDS distribution. The 1,000,000 year pseudo-equilibrium heads and brine concentrations are used as the initial condition for the paleoclimate simulations. Over the past 900,000 years, the Canadian Shield has experienced approximately nine episodes of complete glaciation. During the glaciation cycles, the entire Canadian land mass has been covered by a series of continental ice-sheets whose maximum thickness reached 4 km and whose southern extents reached, in some cases, beyond the present-day Canada-U.S. border. The glaciation phase of a single glaciation-deglaciation episode is typically 90,000 years in duration, while the deglaciation portion proceeds relatively rapidly and has an average duration of approximately 10,000 years. Output from the University of Toronto Glacial Systems Model, a continental scale North American glacial reconstruction of the most recent 120,000 year glaciation event developed by W. R. Peltier, is used to supply the paleoclimate boundary conditions used in this paper. Permeabilty reductions due to the presence of permafrost are also considered in the paleoclimate simulations. This paper will demonstrate that the choice of rock properties can significantly affect residual pore water pressures within the rock matrix, as well as the migration of glacial meltwater.

May 1, 2009

By D. Virely, M. Gasc-Barbier, J. Guittard

"The valleys of the Dordogne and the Vézère (France) have been inhabited since prehistoric times, as evidenced by the famous site of Lascaux. A few miles away, the village of La Roque-Gageac is also a very popular tourist destination (about 1.5 million tourists per year): The village is sandwiched between a massive limestone cliff and the Dordogne river. The collapse of a cave roof high above the village in January 2010 led us to characterize instability together for the cave and the whole cliff and propose a adapted instrumentation to monitor the fracture openings in the rock mass that are linked to climatic variations. Measurements have been going on and been recorded for nearly 4 years. They point out the role of thermal stress fatigue in the breakdown of the rock mass. In this paper we describe the site under study, the instrumentation and its main results. INTRODUCTIONThe phenomenon of thermal fatigue has been very little studied as far as rocks are concerned, whereas it is rather well characterized for other types of materials: Elsevier published a journal dedicated to fatigue (International Journal of fatigue). In the case of rocks, thermal phenomena and their impacts on mechanical behavior have been analyzed from a micro-structural point of view, and it is now well-known that an increase in temperature causes a dilatation of crystals (Arnould et al., 2004; Berest & Weber, 1998). This dilatation may lead to the development of inter-granular traction and compression stresses, and if those stresses are greater than fracture strength, inter-granular and intra-granular cracks may take place. On the other hand, the fatigue phenomenon (cyclic repetition of a temperature variation which is less extreme than the one that may lead to this inter-granular or intra-granular fracture) is a phenomenon which has not been much studied.The principal studies on thermal fatigue on rocks come mainly from the field of geomorphology, particularly in connection with the analysis of the evolutions of past climate that can explain the present shapes of those landforms: those studies remained essentially qualitative and not quantitative. Le Ber & Oter Duthoit (1987) proposed a thermal and thermodynamic approach to analyse the disaggregation of rock masses. This analysis is dedicated to the study of paleoclimates and was implemented to better understand the formation of slope deposits in order to propose transfer models permitting the reconstruction of the climactic conditions contemporary to their appearance. Since deterioration in the cliff only appears after several cycles, it means that it is a gradual and irreversible deterioration which leads to an increase of the « disorder ». Seen from a macroscopic system point of view, this irreversible evolution is quantified by the internal creation of entropy."

Jan 1, 2015

"Line Creek Resources Ltd. produces three million clean tonnes per year of metallurgical and thermal coals for the international market. The mining operation, which is located in the mountains of southeastern British Columbia, produces coal from four pits by conventional truck and shovel methods.The South Pit, which has been in operation since J982, has a benched highwall 490 m in height. Shallow dipping coal seams at the base of the syncline formation will be exposed in the highwall over the next four years of pit life. The first of these seams, which will measure 500 m in final highwall length, was exposed in J994. An auger, powered by a 1250 hp engine capable of cutting 2.2 m diameter holes, was brought on site in J994 and has proven to be a successful means of recovering coal from the J3 m thick seam.This paper covers the background to the selection of an auger mining method to recover highwall reserves together with the geotechnical and methane considerations for this approach.IntroductionLine Creek Resources Ltd., a wholly owned subsidiary of Manalta Coal Ltd., owns and operates the Line Creek mine. The operation which consists of four active pits, a processing plant, and rail loadout is located in the southeastern coal fields of British Columbia. Figure 1 shows the general area.The coal bearing sequence at the mine is preserved on the east and west limbs of a major syncline. Up to twelve mineable coal seams, ranging in thickness from 2 m to 15 m are contained in the formation. Within the pits the seams are stratigraphically consistent and structurally undisturbed, except for small-scale thrust faults that create multiple repeats of the seams."

Jan 1, 1995

By Craig H. B. Leitch

"In describing the alteration of porphyry systems, the term ""secondary K-feldspar"" appears to be an oversimplification. A better term would be ""alkali feldspar"" alteration, because in actual fact the replacement feldspars show gradational changes from an albite, which is important in some systems, to an alkali feldspar containing minor orthoclase molecule, to true orthoclase.There are several textural varieties of secondary alkali feldspar present in the porphyry systems studied from British Columbia, Australia and New Zealand. These include, in apparent increasing order of alteration intensity: clear albite (An10); patchwork albite (An5-10); chessboard albite (An0-10); ""irregular albite "" (An0Ab100 to Ab90Or10); untwinned ""anoralbite"" (Ab90Or10 – Ab70Or30); and orthoclase (Ab40Or60 - Or100)·The exploration significance of these varieties of alkali feldspar is that their gradation in composition, from sodic to potassic, may be linked to a corresponding increase in intensity of alteration. Thus, there is a tendency for more sodic alteration feldspars to characterize weak, sub-economic deposits, or the fringe zones of stronger deposits; the more potassic alteration feldspars may provide an exploration vector toward more highly mineralized zones."

Jan 1, 1981

By Craig H. B. Leitch

"In describing the alteration of porphyry systems, the term ""secondary K-feldspar"" appears to be an oversimplification. A better term would be ""alkali feldspar"" alteration, because in actual fact the replacement feldspars show gradational changes from an albite, which is important in some systems, to an alkali feldspar containing minor orthoclase molecule, to true orthoclase.There are several textural varieties of secondary alkali feldspar present in the porphyry systems studied from British Columbia, Australia and New Zealand. These include, in apparent increasing order of alteration intensity: clear albite (An10); patchwork albite (Ab5-10); chessboard albite (An0-10) "" irregular albite "" (An0Ab100 to Ab90r10); untwinned "" anoralbite"" (Ab90Or-Ab70Or30); and orthoclase (Ab440Or60-Or100)·The exploration significance of these varieties of alkali feldspar is that their gradation in composition, from sodic to potassic, may be linked to a corresponding increase in intensity of alteration. Thus, there is a tendency for more sodic alteration feldspars to characterize weak, sub-economic deposits, or the fringe zones of stronger deposits; the more potassic alteration feldspars may provide an exploration vector toward more highly mineralized zones."

Jan 1, 1981

By A. Singh

Deformation structures after tensile and compression tests on Mg926Zn64Y alloy extruded at 250°C and 400°C are studied, in as-extruded and heat treated conditions. The icosahedral phase particles stimulate recrystallization during extrusion, resulting in fine grain size. Tensile and compression tests at room temperature show comparable yield strength, with a yield asymmetry ratio up to 0.98. c-type dislocations are observed in the grains near the submicron size icosahedral phase particles. The source of these dislocations is believed to be dissociation of <c+a> type non-basal dislocations. No dislocation pile-ups on icosahedral phase particles are found. {10 1 2} type twinning occurs in compression.

Jan 1, 2006

By J. M. R. Carvalho, M. T. A. Reis, M. R. C. Ismael, M. J. N. Correia, S. M. C. Santos, J. M. Carvajal

A sulphide zinc concentrate (Zn-40%) has been leached in sulphuric and chloride media to optimize the conditions for the recovery of zinc and copper. Previous results showed that extractions of 95% zinc and 20% copper can be achieved in just one stage, after two hours of leaching at 80°C with a solution 0.5M in Fe2(SO4)3 and H2SO4 and a solid/liquid ratio of 5%. This work presents the results obtained in the leaching experiments carried out in sulphuric and chloride media using two and three crosscurrent stages and a countercurrent process simulation for a solid/liquid ratio of 10%.

Jan 1, 2008

By R. D. Clark, Heinz Althoff

"The advantages and disadvantages of a mobile crushing plant with a belt conveyor system compared to a stationary crushing plant with haulage by heavy trucks are described. The capital expenditure and operational expenses are compared and the individual cost factors are explained.Every open-pit mine or quarry, however, is different and has to be assessed and analyzed individually in order to find the optimum and most economical solution. Due to the high truck haulage costs, many open-pit mines tend to the more economical solution with mobile crushing plants and continuous belt conveyor operation. IntroductionFor the material haulage within an open-pit mine the heavy truck is the most flexible means of transportation. However, due to the high fuel consumption, wear and labour costs, it is also the most expensive one. Therefore, many open-pit mines are looking for alternative solutions for the material transport A mobile belt conveyor system is most likely to meet the requirements because it is efficient and economical with regard to the power consumption. The material , however, has to be crushed at the mining face to lumps which are suitable for conveyor operation. For this purpose a mobile crushing plant is required.In some open-pit mines the crusher is also used to crush the material to lumps of smaller particle sizes in order to save crushing costs in the preparation plant.Although a cost comparison between a system with stationary crusher and truck haulage and a system with mobile crusher and belt conveyors favours in most cases the belt conveyor system, up till now only a few open-pit mines and quarries benefit world-wide from the advantages of the mobile crushing plant with continuous belt conveyor operation."

Jan 1, 1986

By J. Yue

The particle breakage kinetics, product size and size distribution, as well as grinding limit for quartz suspensions in a horizontal stirred mill are investigated. Results of grinding studies on quartz suspensions in a horizontal stirred mill confirm "first-order" particle breakage rates. A comparison of equation fits reveal that the product size distribution from stirred mill is best represented by the Rosin-Rammler equation when compared to the Gaudin-Shuhmann equation, but results fit poorly as particle size below five microns. A method of determining breakage rates versus particle size is demonstrated which shows that the 10% top size fraction is most appropriate for the determination of specific breakage rates. The method is used to demonstrate the relationship between particle breakage rate and particle size. As the feed particle size becomes smaller, the size reduction ratio decreases and approaches a grinding limit which depends on the effective stresses created in the mill.

May 1, 2004

By Yuki Tsunazawa, Sho Fukui, Chiharu Tokoro

"A milling process is one of the important unit processes in mineral processing. In the milling process, the control of particle size distribution is necessary for the later physical separation process. Since the milling process is strongly affected by the equipment designs, operation conditions and raw materials, the control for particle size distribution of milling products is mainly based on empirical rules. Recently, the discrete element method (DEM) has been widely used as an effective tool to investigate the behavior of grinding media. Although the behavior of grinding media can be accurately simulated, it is not well-established the way to predict particle size distribution after milling by the DEM simulation.The objective of this study was to develop a new method to predict particle size distribution in ball milling using the DEM simulation. To predict particle size reduction, a correlation between experiments and the simulation was investigated in various operation conditions, that is, wide range of the rotation speed and the filling ratio of grinding media. In experiments, after lime stone was ground, the average and variance of particle size distribution were evaluated using some kinds of distribution equations. In the DEM simulation, direct simulation of particle disintegration in milling process is generally very difficult because of huge computational load. Therefore, collision energy between grinding media balls orgrinding media ball and wall was used as a factor of particle disintegration.As a result, a good correlation between experiments and simulation was obtained. In addition, the particle size distribution in ball milling could be predicted using this correlation. Therefore, these results indicated that the use of the correlation between experiments and the DEM simulation was an effective approach of predicting the particle size distribution in milling process."

Jan 1, 2016

By Jarret Thomson

An understanding of groundwater flow is essential for many aspects of mining. This is especially true for the process of shaft sinking through the sandstones of the Manitou Falls Group in the Athabasca Basin of northern Saskatchewan. Experience has shown that the hydraulic conductivities of these sandstones can be relatively high, especially in zones containing natural fractures. To develop a better understanding of the inflow potential into a shaft, a laboratory testing program was undertaken to investigate the hydraulic conductivity of fracture core samples from the Manitou Falls Group. This program involved the measurement of hydraulic conductivities under steady-state flow conditions, while cycling the effective confining pressure across a span that is representative of in-situ conditions. The change in fracture aperture was simultaneously recorded at each confining stress level. It was found that existing relationships relating aperture and flow did not accurately capture the behavior of the samples tested. The effects of fracture staining and infilling were also investigated, and were found to have a notable impact on the hydraulic conductivity.

Jun 1, 2012

By P. R. Stephenson

Mining projects depend on the amount and quality of the mineral reserves, which in turn depend on the amount and quality of the mineral resources. Only Measured and Indicated Resources may be converted to mineral reserves and Inferred Resources may not, with certain exceptions, be used in economic studies. Responsibility for the estimation of mineral resources rests with the Qualified Person (QP) and there is a wealth of literature, text books and case studies to guide the QP. Responsibility for the classification of the mineral resources also rests with the QP. While there is some industry guidance and common practice on approaches to resource classification on which the QP can draw, the process is (or should be) heavily dependent on the exercise of judgement by the QP. However, this inevitably leads to situations where, for example, one QP?s Inferred Resource is another QP?s Indicated Resource. If the QP?s judgement is poorly reasoned or illogical (as is sometimes the case), it can have a major impact on the project, often with substantial cost or value implications. Project managers and company executives should not unquestioningly accept QP?s classification decisions and should apply the same intensity of due diligence that they apply to other critical elements of the project.

May 1, 2011

By A. McLean, J. Hou

Waste slag is a major environmental concern within the metallurgical industry. In the steel industry, about 100 kg of slag is produced in making one tonne of liquid steel from iron in addition to that produced during ironmaking. The amount of slag from the steelmaking converter can be significantly reduced when charging hot metal with low phosphorus and sulphur contents. In this context, hot metal pretreatment is known as an effective means of preparing high quality charge material for the converter thus limiting the generation of residual slag during the steelmaking process. In the aluminum industry, about 2-4 tonnes of slag, including red mud from alumina production and dross from aluminum electrolysis and casting, are generated during the production of one tonne of aluminum. In recent years, reuse of waste slag from the aluminum industry is a topic that is receiving increasing attention. In this paper, the possibilities of using waste slag and by-products from the aluminum industry as a refining flux in the steel industry are discussed. Several successful processes to convert waste materials from the aluminum industry to steel refining fluxes are described. Some theoretical aspects of using calcium aluminate based flux for desulphurization are outlined together with results obtained from laboratory experiments on sulphur removal from hot metal. By intelligent use of waste materials, the disposal of solid waste from the metallurgical industries can be reduced.

Jan 1, 2004

By Tony Lipiec, Ian Orford

"A key part of plant design is the selection of the design tonnage which is the hourly tonnage target that the equipment selection is based on. Its selection is critical for ensuring that the nominal tonnage which is critical to the financial performance of the project will be met. With deposits being developed at lower grades, higher tonnages and a higher degree of hardness variability, it is essential to ensure that the design process selects the comminution equipment which will be able to deal with the impact of this ore quality variation.Ore hardness and its variance are key factors to be taken into consideration for the selection of the design tonnage. It is well accepted that for the nominal or name plate tonnage to be consistently achieved, it is necessary to base the design tonnage on a hardness value greater than the average ore hardness of the deposit to be mined. The question is how much greater should this design value be to ensure that the nominal tonnage is met to the satisfaction of the project financial model. Standard industry practice is to set the design tonnage by:1. Select an ore hardness percentile that is greater than the average ore hardness to be the basis of the nominal tonnage. Typically either the 75th or 80th percentile value from the data set will be selected.2. Selection of a design factor to multiply by for determining the design tonnage, i.e. the design tonnage = tonnage (based on the average ore hardness) multiplied by design factor.This paper discusses the selection of the design ore hardness through the use of modelling or the use of a design factor. It further shows the impact of ore hardness variance on the capacity of the process and its ability to meet the nominal tonnage. Insight is provided as to what ore hardness percentile value should be selected balancing the shortfalls of tonnage for ores harder than the design value versus the above target production achieved for ores softer than the design ore hardness."

Jan 1, 2016

By S. H. Castro

Molybdenite depression by shear degraded polyacrylamide solutions has been investigated. Aqueous solutions of polyacrylamide-type flocculants were subjected to shear degradation under a range of high-speed stirring conditions. Settling tests, carried out with quartz slurries and sheared polyacrylamides, showed reduced flocculant performance with increased degradation. As the sedimentation rate is strongly dependent on the polymer&apos;s molecular weight, these results fit well with the shear degradation theory, which predicts the production of shorter chain segments due to breakage of the polymer macromolecules. Microflotation tests on natural molybdenite showed that the depressing ability of a commercial polyacrylamide flocculant remained unaltered after shear degradation, even when the flocculating ability was entirely lost. Practical implications of shear degradation on molybdenite flotation are discussed.

Jan 1, 2004

By David Lewin

The journey toward cleaner coal-fired power generation is driven by technological improvements, more stringent regulations around greenhouse gas and other air emissions, and the potential of one of Canada?s most abundant resources. Within this context, EPCOR is leading efforts to commercialize gasification technology to produce electricity with near-zero emissions. By turning coal, oxygen, and water into synthesis gas through a gasification process ? and then capturing CO2 ? it is possible to dramatically reduce greenhouse gas and smog-related emissions. EPCOR is conducting front-end engineering and design work on an Integrated Gasification Combined Cycle technology (IGCC) utility-scale plant ? in conjunction with the Canadian Clean Power Coalition ? at its Genesee site, west of Edmonton. EPCOR, the Alberta Energy Research Institute, and Natural Resources Canada have each contributed $11 million to the $33 million project. A critical element of the project features the capture of CO2, which would be piped underground for long-term sequestration, or for use in enhanced oil recovery (EOR). The combination of IGCC and CO2 sequestration, at this scale, has not been used anywhere else in the world.

May 1, 2008

By Aysan Molaei, Kristian E. Waters

"Solvent extraction is the one of the most common techniques for recovering metal ions from aqueous systems. However, it is not efficient in the extraction of low concentration metal ions from aqueous solutions. Predispersed solvent extraction (PDSE) is an alternative method for solvent extraction which implies colloidal liquid aphrons as extracting agents in order to reach higher interfacial area and lower reagent consumption. This work investigated important parameters in PDSE of nickel ions from dilute aqueous solutions by fractional factorial design of experiments. Four experimental parameters, the initial extractant concentration, initial surfactant concentration, equilibrium pH and phase volume ratio (organic to aqueous ratio) were investigated. The important parameters were determined as well as important interactions between these parameters. It was found that extractant concentration, phase volume ratio, and equilibrium pH are the most significant experimental parameters. However, the interaction between surfactant concentration and other parameters was determined as significant interactions.INTRODUCTIONNickel is one of the key components found in cars, mobile phones, rechargeable batteries, kitchen appliances, and steel industry (Anyadike, 2002). It is one of the most important metals produced by Canada which is in the five top nickel producers in the world. Despite a 24% decrease in the nickel prices from 2011 to 2014 the nickel global mine production increased by 36% between these years (U.S. Geological Survey, 2015; Nickel - Statista Dossier, 2015), which shows the increasing demand for nickel. This high demand leads producers to consider the production of nickel from low grade ores and other secondary sources such as process wastewaters. The removal of nickel ions from process wastewater is also important due to environmental considerations. Nickel is known to be a human carcinogen and it may cause serious lung and kidney problems, pulmonary fibrosis, gastrointestinal distress, and skin dermatitis if it exceeds the critical level (Borba et al., 2006; Fu & Wang, 2011)."

Jan 1, 2016

By Joseph Licavoli, Paul Sanders, Yang Yang

"Al-Sc-Zr alloys form thermally stable L12 precipitates which provide high temperature strength. Although the overall fraction of L12 Al3Sc and Al3Zr may be increased by increasing scandium (Sc) and zirconium (Zr) content, such additions may increase primary phase fractions and do not produce desirable secondary phase morphologies. Rapid solidification techniques, such as melt spinning, increase solute atom concentration within the matrix. When the supersaturated matrix is aged, higher precipitate volume fractions at low Sc and Zr levels can be achieved improving high temperature strength. Melt spinning was used to rapidly solidify (107 k/s) a thin ribbon of Al-0.5Sc-0.4Zr at. %. The ribbon was compacted and extruded into 99.8% dense rods, and then aged using multi-step isochronal heat treatment up to 600°C. Precipitation strengthening was evaluated by ambient hardness measurement. The ambient hardness of melt-spun ribbon after precipitation hardening increased by 450 MPa (~67% increment) during isochronal heat treatment.INTRODUCTION Small Sc and Zr additions to aluminum improve strength and creep resistance above 300°C due to tri-aluminide precipitation of Al3(Sc,Zr) in L12 structures similar to ??, Ni3(Al,Ti) in nickel superalloy, but the Al3(Sc,Zr) particles have a Sc-rich core surrounded by Zr-rich shell (Figure 1). The Al3Zr shell limits atomic transport between the Al3Sc core and the matrix and reduces coherency strain. These factors reduce precipitate coarsening rate at elevated temperature (Bergner & Van Chi, 1977; Fujikawa, 1997; Knipling et al., 2011; Clouet et al., 2006).Figure 1. Simplified schematic model of precipitate Al(Sc,Zr) in Al-Sc-Zr alloy. Shell is rich of Al(Zr) intermetallic phase, particle core is rich of Al(Sc) intermetallic phase (after Voorhees, 2006). Numerous Al3(Sc,Zr) particles increase alloy strength and creep resistance as the precipitates impede dislocation glide and to a lesser extent climb. Previous work on ternary Al-Sc-Zr alloys show large strength increases versus binary Al-Sc, and Al-Zr alloys in Table 1."

Jan 1, 2018