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By J. L. Jambor, E. J. Reardon, E. C. Appleyard, J. A. Cherry

Abstract- Since the 1957 initiation of deposition of mill tailings at the Heath Steele mine, New Brunswick, periodic detailed studies of the tailings geochemistry and mineralogy have been con­ ducted, thereby providing a unique opportunity to examine the geochernical evolution of a sulfide- rich mine-tailings impoundment. When deposited, the tailings contained about 85 wt% sulfide minerals, 1 wt% to 3 wt% carbonate minerals, and 12 wt% to 14 wt% aluminosilicate minerals. Mineralogical examination of samples of the tailings from deep in the impoundment indicates that little oxidation occurred prior to tailings deposition. The mill process-water deposited with the tailings was neutral to slightly basic and contained low concentrations of Cu, Pb, Zn and As. Sampling of the tailings five years after deposition indicated that sulfide-oxidation reactions, occurring near the tailings surface, had decreased the tailings-water pH and increased the concentrations of Fe, SOi-, Cu, Zn and Pb (up to 10 000 mg/L, 25 000 mg/L, 2.5 mg/L, 200 mg/L, and 4.5 mg/L, respectively) . In 1975, ten years after decommissioning, the tailings could be divided into three zones: an upper oxidation zone in which sulfide oxidation is actively occurring, a hardpan layer, 15 cm to 20 cm thick, composed of tailings cemented by secondary Fe minerals, and an underlying reduction zone in which the tailings are relatively tinoxidized (Boorman and Watson, 1976). Chemical analyses indicated the presence of low-pH waters containing very high concentrations of SO42- , Fe, and other metals (up to 63 600 mg/L SO42-, 28 600 mg/L Fe, 10 mg/L Pb, 600 mg/L Cu and 4000 mg/L Zn), suggesting that there was a period of intense sulfide oxidation between five and ten years after tailings deposition. More recent sampling, conducted some 20 years after the end of tailings deposition, indicates that relatively little change has occurred in the last ten years, thereby suggesting that the hardpan layer has provided an impediment to the downward movement of dissolved constituents . Analyses of the tailings solids show increased accumulations of many metals at or near the depth of the hardpan layer. Evaluations of the long-term evolution of the tailings can be enhanced by comparison of descriptions of the tailings with descriptions of the gossan that overlay the massive­ sulfide orebody prior to mining. At Heath Steele, this comparison suggests that many of the mechanisms controlling the distribution of metals in the tailings will probably persist over geologic time.

Jan 1, 1992

By J. C. Gibson, C. H. Stockwell

"The San Antonio gold mine is at Bissett, Manitoba, on the north shore of Rice lake, 100 miles northeast of Winnipeg. Gold was discovered on the property in 1911, but intensive exploration was not undertaken until 1926. Milling commenced on May 1st, 1932. Total amount of ore milled from that time until the end of 1946 was 1,766,670 tons, having a value of $18,378,317.GENERAL GEOLOGYThe rocks in the vicinity of the mine are Precambrian and include three groups, namely, the Rice Lake series of volcanic and sedimentary rocks, basic and acidic intrusions, and a younger formation of sediments known as the San Antonio formation (Fig. 1). The lower part of the Rice Lake series, consisting of flows of rhyolite, trachyte, and andesite with interstratified beds of agglomerate, occupies an area extending southward from Rice lake. The lake itself and the country to both east and west of its northern end is underlain by the next succeeding beds of the series, which are chiefly tuffs, arkose, and conglomerate, but include a thin band of basalt. Northward from the lake, these are succeeded by the upper beds of the series, first a thin band of basalt and, overlying this, porphyritic andesite flows interlayered with beds of volcanic breccia or agglomerate.The Rice Lake series has been invaded on the east side of the lake by a body of basic rock ranging in composition from gabbro to diorite and quartz diorite, now much altered. This is cut by younger sills and dykes of basic rock, probably diabase, the original texture of which is largely destroyed by alteration. Numerous dykes of feldspar porphyry, quartzfeldspar porphyry, and a few of a rhyolite-like rock, occur south of the lake, but are uncommon to the north. They cut the diabase and older rocks.Extending westward from Rice lake and lying with marked angular unconformity against all of these rocks is the San Antonio formation, consisting of cross-bedded, arkosic quartzite."

Jan 1, 1954

By J. C. Allan

THE purpose of this paper is to outline the pogress made in the development o the gravity separation method o ore dressing known as Sink-and-Float, which, in the opinion of the writers, has now reached a stage justifying the claim that this new method marks a highly important advance in the technique . The essential feature of the newest development of this process is the extremely accurate separation achieved. This is responsible for higher extraction in the sink-and-float unit on coarse sizes and, in consequence, for substantially higher overall recoveries. Whilst this is the most remarkable feature of the new process, it has further important contributions to make to ore dressing under the following heads: (1) The introduction of the sink-and-float separator as a buffer helps to iron-out irregularities in the mill feed. By supplying a concentrate of constant grade to the flotation section, the process also indirectly improves overall recovery. (2) The addition of a sink-and-float unit to an existing mill results in substantial increase in capacity at low per ton capital cost. (3) Where the plant can be installed underground for the pre-treatment of low-grade ores, there is a saving in hoisting costs, and excellent 'fill' is provided near the point of use. ( 4) Low-grade mixed oxide-sulphide copper ores may be pre-concentrated, thereby producing a flotation feed sufficiently rich to render the oxide residue from such flotation economic for subsequent treatment by leaching or other methods. (5) Application of the process eliminates hard gangue constituents which cause high grinding costs, or gangue constituents which adversely affect flotation. The plant is compact and easily controlled. No highly skilled operators or expensive reagents are required, and the labour and power per ton are low. The separator is extremely flexible, working equally efficiently on any throughput up to its maximum capacity.

Jan 1, 1940

"Energy efficiency in mining and minerals processing has attracted considerable public and industry attention because of the significant quantities of energy consumption involved. In this context the question of what are worthwhile targets for energy efficiency improvements ought to be of the highest priority. It is however worth taking a step back to avoid falling in the trap of taking preconceived ideas that have been reiterated repeatedly before as gospel. The aim of this paper is to highlight areas where new or alternative approaches could potentially be the better way forward. Some may come as a surprise to conventional industry thinking. Ultimately any such solutions are attractive to practitioners not just in an environmental but also in an economic sense, and hence should be targeted through applied research and development efforts. This paper highlights key aspects of each group of opportunities and some of the individual approaches to provide an overview of the current status quo.MINING INDUSTRY POWER UTILISATION – WHERE IS THE BIGGEST BANG FOR THE BUCK?The question of where is the biggest bang for the buck when trying to determine worthwhile targets for energy efficiency improvements has not always been reported on broadly enough, typically because industry practitioners operate in specific areas of expertise and comfort zone. Looking beyond the familiar doesn’t always come easy. Any technology or methodology consideration to address energy efficiency needs to take into account the context of alternative opportunities of superior value or risks not achieving desired uptake. The following sub-chapters have been ordered by magnitude of improvement potential as best as is possible, starting with the biggest first, and the smallest last. Some may be a surprise relative to conventional mining industry thinking."

Jan 1, 2016

By K. C. Corin, Z. G. Song, J. G. Wiese

In the present study the effect of using different grinding media, viz, ceramic balls, forged steel balls, 15% Cr steel balls, stainless steel and mixture of stainless steel and 15% Cr steel balls (50:50) on the flotation performance of a Platinum Group Mineral (PGM) UG2 ore was investigated. Test work was conducted using a laboratory scale horizontal tumbling mill and a batch flotation cell. Power draw to achieve a specific P80 was determined for each media type. Changes in flotation behaviour were evaluated in terms of particle size distribution, water recovery, solid recovery and valuable mineral recovery. pH, Eh and DO levels were also measured. Grinding products of five different media produced similar solids and water recovery, which is indicative of the froth characteristics, but the grades and recoveries of PGE and chromite were different. The product obtained when using ceramic media showed the best flotation performance, producing the highest PGE recovery and the lowest Cr2O3 recovery. The products obtained when using stainless steel balls (SS) produced the lowest PGE recovery and highest Cr2O3 grade and recovery. The paper proposes possible reasons to explain these observations which may have significant importance for the operation of a PGM concentrator.

Jan 1, 2015

By Michael Harley, E. Guy Charlesworth

"Abstract - Bedding-parallel thrust-hosted gold veins are developed in the Sabie-Pilgrim's Rest goldfield, eastern Transvaal, South Africa. The reefs display a complex history characterized by temporally and spatially overlapping events of similar mineralization and deformation. Recognition of the episodic reactivation of these low angle (5° to 10°) thrust faults implicates high fluid pressures (equalling or exceeding lithostatic pressures). Geochemical constraints limit the amount of fluid-rock interaction and the occurrence of transgressive mineralization within the Archaean granitoid basement suggests that the high pressure fluids originated at depth beneath the Transvaal Basin.Similarities exist between gold deposits of Sabie-Pilgrim's Rest and Telfer, Western Australia as well as Passagem de Mariana, Minas Gerais, Brazil. All deposits are sub-parallel to the enclosing bedding which is shallowly inclined. Furthermore, they are also hosted by contractional deformational structures and are clearly epigenetic in origin."

Jan 1, 1994

By J. M. Harrison

FIELD PARTIES of the Geological Survey of Canada have, in recent years, mapped several areas east and northeast of Flin Flon (9, 10, 12, 13, 14, 15, 118) (1). In all these areas the mineral deposits show a close geographical relation to faults although the immediate control of most of the known ore deposits appears to be folded structures in the rocks (8, 11, 18, 19). Air photographs and published geological maps were studied in order to ascertain whether or not the mineral deposits in the Flin Flon-Snow Lake mineral belt as a whole show any spatial relationship to faults. It was found that most of them do show a distinct geographical association with faults, or with topographic features that may be faults. It is further apparent on air photographs that a major lineament, for composite of lineaments, follows approximately the contact between gneisses and schists of the Kisseynew complex on the north, and Amisk volcanic rocks on the south. However, this Kisseynew lineament is not continuous and, especially in the eastern half of the district, it is exceedingly irregular in plan. Parts of this lineament have been mapped as faults (9, 10, 12, 14), other parts have been shown as stratigraphic contacts (1, 2, 21, 27), and still other parts have not been studied except by reconnaissance methods. It is suggested that the Kisseynew lineament may be due to a deformed fault that extends easterly from a point about 25 miles west-northwest of Flin Flon to a point at least 10 miles northeast of Wekusko lake and that the mineral deposits.

Jan 1, 1951

By The Hollinger Mill Staff

MR. E. L. Longmore (l), in presenting this paper at the Annual General Meeting, suggested that it was neither desirable nor necessary to read any but the briefest portion of the paper. He wished to emphasize that the scale of the milling operations at the Hollinger not only provided several units in continuous operation to ensure that the test work was being carried on under normal conditions, but also provided a large and competent staff to supervise such an extensive experiment and to criticize intelligently the recorded results. He wished to acknowledge the enthusiastic co-operation of the group of assistants whose excellent work was responsible for the confidence with which the conclusions could be presented. The following data were given as a supplement to the published paper. Following conclusion of the test work described in the paper, the size of the balls fed to the mill was changed from 3-in. diameter to 2Yz-in. Within a short time, a gradual rise in the tonnage rate took place and, as no other condition had been changed, the increased tonnage was credited to the changed character of the ball load. At present, the average daily tonnage for the mill with low discharge is 1,507 tons, an increase of 77 tons over the 1,430 tons ground when feeding a 3-in. ball. A similar increase in tonnage should be credited to the high-discharge test, if the 2;Y2-in. ball had been used at that time. This would raise the 1,117 tons ground at that time to a new figure of 1,177 tons. From a study made to determine those factors influencing the rate of pulp flow through the low-discharge mill, it became evident that the ball screen used on the high-discharge mill must have been restricting the flow through the mill, although this was not recognized at the time. Accord-ingly, it was decided to repeat the high-discharge run. Additional length was added to the 21-in. ring grizzly originally used, and the length of the reverse spiral was increased. The end of the grizzly was left open so that, if necessary, excess pulp might flow out. A coarse mesh 3 ft. by 3 ft. flat screen was provided to catch stray balls.

Jan 1, 1937

By M. Sanchez

In the last decades, the Chilean copper mining and metallurgical industry have had to modify their technological processes to meet the environmental regulations implemented by the Chilean government, and also to support the pressure of the public opinion. Thus, air quality standards for sulfur dioxide and particulate matter (primary and secondary), plans for reducing emission of arsenic by the Chilean copper smelters, effluents discharge limits, among others regulations were applied by the environmental agency. Additionally, agreements on cleaner production were carried out by mining sector and government. Now, a draft law on mine closure, and another on environmental mining wastes (abandoned mines) are being discussed by the authorities and the mining sector. In the context, production and environmental impacts in different ways to produce copper in the Chilean mining industry are reviewed and regulatory tendencies as well as abatement technologies today used are exposed and discussed in this presentation. Pyro, hydro and electrometallurgical processes employed and their current effluent and contaminants are presented showing various alternatives of treatment in the copper industry. An update of regulations established in Chile vis a vis copper production, with an especial attention to mine closure are also presented.

Jan 1, 2007

By A. M. McKim, J. S. Ambler

"The iron ore of the Scully Mine is upgraded from 36 per cent Fe to 66 per cent Fe through single-stage crushing, wet autogenous milling, sizing by vibrating screens and two-stage spiral separation, followed by a process in which the concentrate is dried and then further improved by high-tension separators. The capacity of the concentrator is 17,000 long tons of concentrate per day. Discussion of the operation will recognize the special problems encountered in handling preponderantly fine ore, relate issues of interest regarding wear and review mechanical innovations found to be advantageous at Wabush. The modern trend toward big equipment, thoroughly instrumented, has been the theme of design. Effects on availability must be a consideration in this choice, and sectionalizing of circuits to minimize these consequences is as important as streamlined maintenance."

Jan 1, 1969

By R. Amata

"The Gakara Rare Earth deposit in Burundi (East Africa) is unique for its high grade (e.g., 54.3% TREO on average) and low uranium and thorium levels. The majority of the light rare earth (RE) elements in material from Gakara are contained within the familiar RE minerals bastnaesite and monazite. Extensive metallurgical test work was conducted by SGS Minerals Services on mineral samples collected from the Gakara deposit. Various whole ore hydrometallurgical processing routes were examined in a scoping level test program. Preliminary beneficiation testing was also conducted, though it was determined that only marginal upgrading would be achieved with significant RE losses. Thus a hydrometallurgical process on whole ore was developed to minimize the overall process complexity and achieve maximum RE recovery. Results from the test work will be presented, along with the selected base case flowsheet involving agitated atmospheric sulphation of the RE minerals, RE double sulphate precipitation, caustic conversion, redissolution, and carbonate precipitation. Following the base case flowsheet, a purified cerium free mixed RE carbonate with low levels of radioactive elements was produced.INTRODUCTIONRainbow Rare Earths Limited (Rainbow) is a mining company engaged in the exploration and development of the Gakara rare earth deposit in Burundi; Figure 1 shows the project location. The project is located in the Bujumbura Province and 45 km from the Burundi capital of Bujumbura. Notable for its exceedingly high in-situ grade – 54.3% on average total rare earth oxide (TREO), low uranium and thorium levels and familiar rare earth minerals, bastnaesite and monazite – Gakara is the world’s richest rare earth deposit. The project, a previously operating mine from 1948–1978, has a significant mineral inventory base, a long life of mine, well understood mineralogy, and robust economics. Rainbow is focused on bringing Gakara into production in the near term, ramping up to produce 5,000 t/y of a 54%+ TREO concentrate."

Jan 1, 2016

By S. B. V. Stewart, W. W. Forsyth

"Since the Mathew's method for open stope design was first proposed by Golder Associates in 1980 it has been applied at a number of mine sites in Canada. The initial hypothesis was based on a relatively small amount of data and the intervening period has allowed the collection of a significant amount of new data to test the validity of the method.This paper examines a brief history of the evolution of rock mass classification systems to provide background and emphasize their empirical and non-rigorous approach. It also presents the new data which appear to indicate that the initial hypothesis was reasonably good. The modification to the original graph proposed by Potvin is discussed as well as the applicability of the method to predicting the onset of caving. The original graph has been updated and has been subdivided into four zones described as ""stable""; ""potentially unstable""; ""potential major failure""; and ""potential caving"". The method is recommended as a useful open stoping design tool provided it is recognized that it is not a rigorous design method.Finally the paper proposes a recommended approach for application of the method by would-be users and addresses some typical pitfalls that may be encountered."

Jan 1, 1995

By H. B. Farnam

"THE IRON ORE Company of Canada has been using do-it-yourself type explosives for three years. During the last 12 months we have used over 10 million pounds of ammonium nitrate-fuel oil explosives and either purchased or formulated one million pounds of slurried explosives.W e have been moving approximately one million cubic yards of stripping and ore per month and we expect our production rate to in-crease. Eighty per cent of our strip-ping and ore is soft enough to be blasted successfully with ammonium nitrate-fuel oil mixtures. Twenty per cent of our material is extremely hard and requires an explosive having greater strength than an AN-fuel oil mixture.W e had been using canned am-monium nitrate base explosives and TNT pellets to give maximum bottom loading density to fracture hard rock. As AN -fuel oil became widely used, it was apparent that other types of explosives could be formulated to fit our blasting requirements. Dr. M. A. Cook of the University of Utah was consulted regarding new explosives and together we developed the blasting slurries.Figure 1 shows a general view of one of our hard rock pits. The foot wall is on the right-hand side and this material is called iron forma-Figure 1.-General view of hard rock pitstion by our Company but is called 'Taconite by the operators on the Mesabi Range. This material runs 35 to 45 per cent iron and many pieces are hard enough to scratch glass. The formation is tilted at an angle of 55 degrees as can be seen in Figure 3.The bedding planes of this rock are about 24 to 36 inches apart and if the material is not well broken or fragmented, large chunks or slabs must be handled by the shovels which reduces shovel capacity and efficiency and increases maintenance costs."

Jan 1, 1960

By Hatch, A. Reple, W Valery

The mining industry is facing declining feed grades which require the mining and processing of larger volumes of material per tonne of product. Pre-concentration aims to remove barren material at as coarse a particle size and as early in the process as possible to reduce processing costs, energy consumption, water losses, and greenhouse gas emissions while increasing production and profitability. This may be achieved using bulk ore sorting—the separation of barren gangue from a fully loaded conveyor belt based on the grade as measured or inferred from a sensor. This paper evaluates the technical and economic viability of bulk ore sorting for the PanAust Phu Kham copper deposit in Lao PDR. Bulk ore sorting technology is described briefly along with discussion of appropriate sensor and diversion systems for the Phu Kham operation. To evaluate the economic implications, the actual mined material and costs from 2014 were used as the base-case. Sampling data was not available; therefore, the ore grade variability that would feed a bulk ore sorter was estimated using geo-statistical tools based on mine grade control data. The sorter performance when treating this material was simulated considering the accuracy of the sensor measurement and errors associated with material diversion. The impact on inferred cash flow was estimated for several different scenarios considering the additional costs for sorter operation and reject handling. The evaluation demonstrated that bulk ore sorting at Phu Kham has the potential to increase the amount of metal in product and/or reduce processing plant throughput (and costs) to improve the annual inferred cash flow for the conditions investigated. The sorter is the gatekeeper – only material above the cut-off grade (value-adding) reports to the processing plant; no waste dilutes the feed. Likewise, above cutoff grade material is not lost to waste; preventing lost revenue.

Jan 1, 2016

By Waldemar W. Koczkodaj, William O. MacKasey

Abstract - A consistency-driven pairwise comparisons method for mineral potential assessment is presented, using a simplified case of volcanic-associated massive sulfide type deposits as an example. Geological, geochemical, and geophysical criteria are considered on two levels: local and regional. The local geological criteria are subdivided into stratigraphy, lithology, alteration and/or mineralization, and structure. The concept of geomerit index and a procedure for computing this index are introduced. The method of consistency-driven pairwise comparisons can be combined with other quantitative and qualitative assessment methods, enhancing them by incorporation of nonmeasurable geological criteria (e.g., stratigraphy or lithology) and by computation of weights. The consistency-driven approach allows experts to refine at-times subjective judgments concerning exploration and land-use planning, and contributes to the improvement of mineral-potential assessments.

Jan 1, 1997

By Waldemar W. Koczkodaj, William O. MacKasey

A consistency-driven pairwise comparisons method for mineral potential assessment is presented, using a simpli?ed case of volcanic-associated massive sul?de type deposits as an example. Geological, geochemical, and geophysical criteria are considered on two levels: local and regional. The local geological criteria are subdivided into stratigraphy, lithology, alteration and/or mineralization, and structure. The concept of geomerit index and a procedure for computing this index are introduced. The method of consistency-driven pairwise comparisons can be combined with other quantitative and qualitative assessment methods, enhancing them by incorporation of non-measurable geological criteria (e.g., stratigraphy or lithology) and by computation of weights. The consistency-driven approach allows experts to re?ne at-times subjective judgments concerning exploration and land-use planning, and contributes to the improvement of mineral-potential assessments.

Jan 1, 1997

By F. Chevarin

The reaction of O2 with the carbon anode is considered as the main parasitic chemical reaction affecting Hall-Heroult process anodes. The current study aims at investigating the influence of the microstructure of baked anode on its overconsumption. Samples were removed from different positions of an industrial anode. Density, porosity, Lc and BET specific surface area were measured. The anode reactivity was evaluated based on the weight losses for the samples resulting from the reaction of anode with air at 550°C after 7h. The essential parameters determined to control the air reactivity are closed porosity, Lc and pores with a pore entrance radius of 1.5, 8.5 and 12 p.m. The knowledge of effects of these parameters allows better understanding of the reactivity of anodes and consequently reduction of their overconsumption in electrolysis bath.

Jan 1, 2011

By R P. Douglas

During 1955, Cominco commenced an exploration pro-gram in northern New Brunswick; in the following year, what is now the Wedge mine was discovered. The mineralization is mainly pyrite, with associated chalcopyrite and minor amounts of sphalerite and galena. The property was brought into production at 750 tons per day in early 1962. The ore is trucked 10 miles to the Heath Steele concentrator, where a copper concentrate grading about 19.5 per cent is produced and shipped to the Japanese markets through the port of Dalhousie, New Brunswick. Introduction THE Wedge mine, owned by The Consolidated Mining and Smelting Company of Canada Limited (Cominco), is located in the Newcastle-Bathurst area of New Brunswick. It is 42 miles by road northwest of Newcastle and 37 miles southwest of Bathurst (Figure 1). The mine is located on the north side of the Nipisiquit river in one of the more mountainous areas of the Province, the local relief rising to 1,500 feet above sea level. There is an almost complete forest cover of mixed hardwoods and conifers -the val-leys and hillsides being covered by balsam, spruce and pine, the swamps by cedars and black spruce and the highlands by mixed hardwoods.

Jan 1, 1965

By S. A. L. Read

"The intact rock constant, mi, is one of the three basic input parameters required for the widelyused Hoek-Brown failure criterion. Values for the constant should ideally be determined by statistical analysis of laboratory test data. In this paper the influence of the inclusion or exclusion of tensile test data on derived values is discussed. We firstly investigate the relationship between direct tensile strength (DTS) test values and Brazilian tensile strength (BTS) test values based on a literature search, finding that the correlation between the two test types is DTS = 0.9*BTS, independent of the lithology being tested. Secondly, using the shear strength database of Douglas (2002), we examine the influence of confining pressure range and the inclusion or exclusion of DTS and BTS test values on calculated values of mi.Chief amongst the influences was the exclusion of tensile data in the calculation procedure, particularly when the Hoek triaxial confining stress range requirement (?3?max = 0.5?c) was not satisfied. Based on a reasonable 1:1 relationship between R (the ratio of unconfined compressive to tensile strength), use of actual tensile data in the calculations for the Hoek brown failure criterion is considered to be a simpler and more robust approach to the use of a tensile cutoff based on empirical criteria such as that of Fairhurst (1964). We advocate the fitting a failure curve using compressive and tensile test data as the most reliable means of calculating mi, while at the same time satisfying requirements as originally advocated by Hoek relating to the appropriate triaxial confining stress range (?3?max = 0.5?c) and sufficient (>5) evenlyspread data points. In the absence of triaxial data the use of R provides a practical means of obtaining estimates of mi that are more robust than guideline values."

Jan 1, 2015

By X. Q. Jiang, D. L. Chen, A. Macwan

Magnesium alloy, being the lightest structural material, is a key candidate for the weight reduction of vehicles in automotive and aerospace industries; however, its poor corrosion resistance and difficulty in deformation are limiting factors. Recently, Al/Mg/Al tri-layered clad sheets have been considered as a promising alternative to improve corrosion resistance and formability of magnesium alloys. The aim of this study was to evaluate the tensile properties and deformation behavior of Al/Mg/Al tri-layer clad sheets at different temperatures and strain rates. Yield strength (YS), ultimate tensile strength (UTS), and elongation were observed to increase with increasing strain rate. With increasing temperature from -40°C to 180°C, YS and UTS decreased and ductility increased. The strain hardening exponent evaluated via three equations of Hollomon, Swift, and Afrin et al. showed a similar increase with increasing strain rate and decreasing temperature. The fractographic analysis showed partial debonding of clad interface especially at higher strain rates and lower temperatures.

Jan 1, 2015