Secondary Cast Research Articles

LCA of recycling aluminium incineration bottom ash, dross and shavings in a rotary furnace and environmental benefits of salt-slag valorisation

Recycling aluminium in a rotary furnace with salt-fluxes allows recovering valuable alloys from hard-to-recycle waste/side-streams such as packaging, dross and incinerator bottom ash. However, this recycling route generates large amounts of salt-slag/salt-cake hazardous wastes which can pose critical environmental risks if landfilled. To tackle this issue, the metallurgical industry has developed processes to valorise the salt-slag residues into recyclable salts and aluminium concentrates, while producing by-products such as ammonium sulphate and non-metallic compounds (NMCs), with applications in the construction or chemical industries. This study aims to assess through LCA the environmental impacts of recycling aluminium in rotary furnaces for both salt-slag management routes: valorisation or landfill. It was found that this recycling process brings forth considerable net environmental profits, which increase for all the considered impact categories if the salt-slag is valorised. The main benefits arise from the production of secondary cast aluminium alloys, which is not unexpected due to the high energy intensity of aluminium primary production. However, the LCA results also identify other hotspots which play a significant role, and which should be considered for the optimisation of the process based on its environmental performance, such as the production of by-products, the consumption of energy/fuels and the avoidance of landfilling waste. Additionally, the assessment shows that the indicators for mineral resource scarcity, human carcinogenic toxicity and terrestrial ecotoxicity are particularly benefited by the salt-slag valorisation. Finally, a sensitivity analysis illustrates the criticality of the metal yield assumptions when calculating the global warming potential of aluminium recycling routes.

Art and technique of Cuojinyin: Two belt hooks from luoyang of eastern zhou dynasty

Cuojinyin is an inlay technique for delicately decorating the surface of bronze and iron wares. It takes advantage of the ductility of gold and silver to perfectly embed them into prepared grooves on the surface of bronze and iron wares without traces of using adhesives. This paper presents preliminary analyses of two belt hooks with cuojinyin decoration excavated from Luoyang, the capital of Eastern Zhou, dated to the Warring States Period. Non-destructive analytical methods including Ultra-Depth Three-Dimensional Microscope and energy dispersive X-ray fluorescence spectrometer (XRF) were conducted to obtain analytical data and reconstruct the manufacturing process. Several interesting technical features were observed such as the secondary casting of tin–lead alloy, the elemental composition of which is totally different from the bronze surface, and the chasing marks inside the casted grooves for gold and silver inlay. The aesthetic orientation and technical details of cuojinyin not only indicate inspirations from the nomadic world and the long distance interaction across the Eurasia, but also reflect the long developed local tradition in ancient China laid in bronze mold casting technology and turquoise inlay.

Neutron-tomographic study of the structural features of a bronze mirror found in the Akterek burial complex

This work presents a study on the structure of a bronze mirror found in the Akterek burial complex by using neutron radiography and tomography. The manufacturing features and the physical state of this mirror was analyzed by three-dimensional model. It turned out that the rim on the edge was made of a different alloy, and the border between the rim and the base of the mirror is also visually visible. The morphological features and spatial distribution of pores and voids formed during secondary casting with the application of various patterns and ornaments have been studied in detail. The neutron tomography data made it possible to study the remains of a thin layer of corrosion on the surface of the mirror.

Corrosion and tribocorrosion protection of novel PEO coatings on a secondary cast Al-Si alloy: Influence of polishing and sol-gel sealing

PEO coatings have been developed on a secondary cast Al-Si alloy, using a novel aluminate-based electrolyte, containing Na4P2O7, Na2WO4 and K2TiF6. The protective performance of the PEO coatings has been improved throughout the application of two post-treatments: polishing of the outermost coating layer and sealing with a sol-gel layer. While the sol-gel has notably improved the corrosion resistance and dielectric properties, due to the sealing of surface pores, the decrease in surface roughness achieved by polishing have enhanced the tribocorrosion performance. The post-treatments studied would enable the future application of PEO coatings on components with high requirements in corrosive environments.

Comparative study on some structural properties of Ni- and Co base dental alloys produced by thermal alloying and powder metallurgical methods

This paper presents the results of comparative studies of nickel- and cobalt base dental alloys obtained using both the classical high-temperature alloying and the powder metallurgy (PM) methods. Structural properties of alloys were used using XRD, SEM/EDX methods of analysis. The studies examined both primary and secondary cast specimens of the two alloy types. Some advantages of the PM technology are discussed.

High performance tribological coatings on a secondary cast Al–Si alloy generated by Plasma Electrolytic Oxidation

Due to their outstanding properties, including low density or high-strength-to-weight ratio, cast Al–Si alloys are attractive materials. Nevertheless, their low wear and corrosion resistance still remain a critical issue for several applications. The present work is focused on the obtention of PEO coatings on a secondary cast Al–Si alloy (EN AC-46500) and the in-depth study of the properties derived from the use of two developed aluminate-based electrolytes.All the obtained PEO coatings have been characterized in terms of their thickness and roughness, morphology, and composition. Reciprocal wear tests have been performed in order to evaluate the tribological behavior of the PEO layers, while their anti-corrosion properties have been analyzed throughout Potentiodynamic Polarization and Electrochemical Impedance Spectroscopy.Our findings suggest that the aluminate-based electrolytes led to an increase in coating thickness of density, while providing a notable improvement on the surface hardness in comparison with the uncoated Al–Si alloy. All the PEO coatings tested exhibited excellent wear resistance and an improved anti-corrosion behavior compared with the uncoated Al–Si alloy. Furthermore, K2TiF6-containing electrolyte promoted the obtention of PEO coatings that provided the highest protection against wear and corrosion to the cast Al–Si alloy treated.

OBTAINING OF HYDRO-INSULATION MATERIALS, PENETRANTS AND OTHER DEFICIENT LOW- TONNAGE PRODUCTS FROM PETROLEUM


 
 
 
 Hydro-insulation of building constructions, different purpose structures is one of the most important and urgent problems of the present day. Currently concrete, ferroconcrete, metal and wooden materials are used for this purpose. Materials of this kind are not produced in the South Caucasian region. Their import, transportation, clearance by the customs and other expenses significantly increase the cost of buildings and makes it unprofitable to use them. Excreted from petroleum products – paraffins and cerezines, petrolatum, luminophores and various purpose binders, can become profitable basis for obtaining of moderm hydroinsulation materials. Their inclusion in modern hydroinsulation compositions will help to increase quality of these materials and to decrease their cost. By mixing of the goudron obtained as a result of rectification of oil pipeline sediments with milled secondary tyre casting, liquid glass, quarz sand and several additives – new hydroinsulation material was obtained.
 
 
 

Analysis of the Mechanical Properties of Secondary AlZnMg(Cu) Die-Cast Alloys

In this work, the development of AlZnMg(Cu) alloys was performed by thermodynamic simulations and experimental tests. With calculations, the solidification processes and phase compositions could be predicted. As secondary casting alloys, the selected compositions of AlZn4Mg3Cu(Fe) and AlZn5Mg4Cu have higher contents of alloying elements, such as iron and silicon, and were successfully processed with a cold-chamber die casting machine. In addition, an energy- and time-saving optimization of the material properties was performed by a modified heat treatment (T6*) with a total time of only 12 h. The alloys were evaluated based on the characterization of their mechanical properties and the analysis of their microstructures. In particular, the elimination of cost-intensive alloying elements and the application of a modified heat treatment method clearly show the potential of AlZnMg(Cu) die-cast alloys for future industrial use.

Wayward Witch by Zoraida Córdova

Reviewed by: Wayward Witch by Zoraida Córdova Kate Quealy-Gainer, Assistant Editor Córdova, Zoraida Wayward Witch. Sourcebooks Fire, 2020 [384p] (Brooklyn Brujas) Trade ed. ISBN 9781492650683 $17.99 Paper ed. ISBN 9781728215518 $10.99 E-book ed. ISBN 9781492650690 $9.99 Reviewed from galleys R Gr. 8-12 Fifteen-year-old Rose Mortiz survived being trapped in hellish Los Lagos (in Labyrinth Lost, BCCB 9/17) and dealing with Lady de la Muerte (in Bruja Born, BCCB 6/18), but healing her broken family and restarting their lives in Queens still feels daunting. She barely gets a chance to try before the affairs of the supernatural world pull her back in (literally, through a portal), this time to Adas, a mythical realm in the Caribbean Sea. A destructive rot is threatening to swallow the island and potentially make its way to Rose's world, and while the king of Adas is a liar and a dictator, he appears to be right when he insists that Rose's ability to steal and amplify other creatures' magic may be able to stop it. Accompanied by the kingdom's warrior princess and bookish prince, Rose makes her way through a fantastical world of beauty and danger to discover that the plague on the land may have more to do with the wreckage of the royal family than any type of dark magic. This final book in the Brooklyn Brujas series shifts focus to the youngest Mortiz sister, and Córdova yet again executes a wholly satisfying combination of deft characterization and cinematic world building. Adas includes elements of Western and Latin American folklore and fairy tales, giving readers a setting both familiar and fresh, and the secondary cast (including a nonbinary character) plays a crucial role in Rose's emotional growth as she realizes that brokenness isn't a permanent state and that scars point towards healing, not necessarily more pain. Readers will be sad to say goodbye to the Brooklyn Brujas, but they could also head back to Los Lagos to start the story again. Copyright © 2020 The Board of Trustees of the University of Illinois

The One and Only Bob by Katherine Applegate

Reviewed by: The One and Only Bob by Katherine Applegate Kate Quealy-Gainer, Assistant Editor Applegate, Katherine The One and Only Bob; illus. by Patricia Castelao. Harper, 2020 [352p] Trade ed. ISBN 978-0-06-299131-7 $18.99 E-book ed. ISBN 978-0-06-299133-1 $10.99 Reviewed from galleys R Gr. 3-5 In this sequel to her Newbery-winning The One and Only Ivan (BCCB 2/12), Applegate shifts the narration from the gorilla Ivan to his best pal Bob, an irascible street mutt who has now been thoroughly domesticated by the zookeeper’s daughter, Julia. Bob’s always thrilled when Julia takes him on a visit to the zoo to see Ivan and their baby elephant friend, Ruby, but one outing takes a dangerous turn when a tornado strikes, separating Julia and Bob, destroying several animal habitats, including Ivan’s, and throwing the zoo into chaos. As Bob searches for his friends, he narrowly escapes danger, makes a few daring saves, and comes face to face with one of the more painful secrets of his life. Much like Bob himself, this book has an appealing mix of frenetic energy and somber contemplation, and the lightning-quick pace (most of the book takes place in the few hours before and after the storm) is tempered by Bob’s flashbacks to his time as a stray, scrapping for food and often seeing the worst in both animals and humans. The mutt’s happy-go-lucky demeanor is belied by quiet pauses of reflection, touched by pain and grief (“There are so many ways the world can find to fail you”), and even the upbeat resolution to his secret comes with its own sorrow. A secondary cast of animals, ranging from a sassy squirrel to a snobby poodle, provides bits of humor, and the rescue scenes add drama and thrills. Commentary on animal welfare and climate change is carefully woven into the narrative, giving readers food for thought but never overwhelming what is ultimately a tale of friendship and forgiveness. Copyright © 2020 The Board of Trustees of the University of Illinois

Armadillo and Hare: Tales from the Forest by Jeremy Strong

Reviewed by: Armadillo and Hare: Tales from the Forest by Jeremy Strong Kate Quealy-Gainer, Assistant Editor Strong, Jeremy Armadillo and Hare: Tales from the Forest; illus. by Rebecca Bagley. Fickling/Scholastic, 2020 [160p] Trade ed. ISBN 978-1-338-54059-8 $16.99 E-book ed. ISBN 978-1-338-60838-0 $10.99 Reviewed from galleys R Gr. 2-4 Ten accessible, episodic chapters introduce young readers to odd couple Armadillo and Hare. Armadillo is slightly cranky and Hare a bit strange, and while we've certainly [End Page 231] seen these tropes before, Strong refreshes them with some playful absurdity, with Armadillo obsessed with painting cheese sandwiches and Hare playing a tuba that pops out flames, butterflies, cabbage, etc. The charming friends are supported by an equally charming secondary cast, as Wombat bops along on her bicycle and does odd jobs (primarily fixing refrigerator lights), Elephant browses Hare and Armadillo's house (eventually destroying a wall), and Jaguar seeks a friend that he won't be tempted to eat. The vocabulary here will certainly test young readers' skills ("illuminated," "liquid" and "phenomenal" are sample stretches) but the gentle, goofy humor will give them a reason to stay. Bagley's airily humorous black and white art perfectly captures the anthropomorphized animals. This is an obvious sell to fans of Frog and Toad, but fans of DiCamillo and McGhee's Bink and Gollie (BCCB 10/10, etc.) may also find these pals easy to befriend. Copyright © 2020 The Board of Trustees of the University of Illinois

Material compositions and production methods for solid cast glass components

Glass can be made by different manufacturing processes and by numerous of varied recipes that in return provide the material with different properties. Owing to their workability in lower melting temperatures and the corresponding decreased manufacturing costs, soda-lime and borosilicate glass types are preferred for cast glass applications in structures. Glass can be cast in two ways: primary and secondary casting. In primary casting, glass is molten from its primary raw ingredients, whereas in secondary casting, solid existing pieces of glass are re-heated until the (semi-) liquid mass can flow and be shaped as desired. The main process of primary casting is hot-forming (melt-quenching) and of secondary casting is kiln-casting. The principal difference between the two methods, besides the initial state of glass, is the required infrastructure. In hot-forming, molten glass from a furnace is poured into a mould and is then placed in another, second furnace for annealing. In contrast, kiln-casting employs a single kiln for the melting of the (already formed) glass into the moulds and for the subsequent annealing process and requires lower operating temperatures. In both methods the annealing process is similar. The annealing schedule is influenced by numerous factors that cannot be easily simulated as a complex non-linear time dependent multi-variable analysis is required. As a result the annealing schedule of large 3-dimensional cast units is commonly empirical. Different mould types, disposable or permanent, can be used for casting glass objects. The choice of mould mainly depends on the production volume and desired level of accuracy of the glass product, and is in practice usually cost and time driven. Currently, there is no standard to determine the design strength of solid cast glass objects for structural applications in architecture. Based on the assumption that the increased volume of cast glass can lead to a higher amount of randomly distributed flaws in the mesostructure, the bending strength of cast glass is expected to be comparable but slightly less than that of standard float glass.

A Formation Map of Iron-Containing Intermetallic Phases in Recycled Cast Aluminum Alloys

The cooling rate-dependent modification effect of Mn on the formation of Fe-containing intermetallic phases during solidification of Al-Si-Mg secondary cast aluminum alloys [containing 0.5 to 1 pct Fe (All compositions are in wt pct unless otherwise stated.)] was investigated by CALculation of PHAse Diagrams (CALPHAD) modeling and solidification experiments. The critical Mn concentration required to prevent the formation of detrimental β-Al5FeSi was found to be dependent on both the alloy composition (particularly the Fe/Mn ratio) and the cooling rate. A map of Fe/Mn ratio vs cooling rate was created, to summarize the metallurgical conditions of Fe-rich intermetallic phase formation. By understanding such formation conditions, the microstructure of aluminum castings can be controlled to create low-cost secondary alloys with high Fe content.

Dependence of Corrosion Resistance for Aluminum Alloys with Composition Increased Impurity Content

The effect of the main impurities, added separately to an alloy, on aluminum-magnesium alloy corrosion resistance, and also in combination on the corrosion properties of secondary cast alloy AMg5K is studied. Comparative tests are conducted for corrosion resistance of industrial silumin and magnalium under different climatic conditions. Experimental results are provided for a study of the effect of alloy composition on corrosion properties under different climatic conditions.

Material compositions and production methods for solid cast glass components

Glass can be made by different manufacturing processes and by numerous of varied recipes that in return provide the material with different properties. Owing to their workability in lower melting temperatures and the corresponding decreased manufacturing costs, soda-lime and borosilicate glass types are preferred for cast glass applications in structures. Glass can be cast in two ways: primary and secondary casting. In primary casting, glass is molten from its primary raw ingredients, whereas in secondary casting, solid existing pieces of glass are re-heated until the (semi-) liquid mass can flow and be shaped as desired. The main process of primary casting is hot-forming (melt-quenching) and of secondary casting is kiln-casting. The principal difference between the two methods, besides the initial state of glass, is the required infrastructure. In hot-forming, molten glass from a furnace is poured into a mould and is then placed in another, second furnace for annealing. In contrast, kiln-casting employs a single kiln for the melting of the (already formed) glass into the moulds and for the subsequent annealing process and requires lower operating temperatures. In both methods the annealing process is similar. The annealing schedule is influenced by numerous factors that cannot be easily simulated as a complex non-linear time dependent multi-variable analysis is required. As a result the annealing schedule of large 3-dimensional cast units is commonly empirical. Different mould types, disposable or permanent, can be used for casting glass objects. The choice of mould mainly depends on the production volume and desired level of accuracy of the glass product, and is in practice usually cost and time driven. Currently, there is no standard to determine the design strength of solid cast glass objects for structural applications in architecture. Based on the assumption that the increased volume of cast glass can lead to a higher amount of randomly distributed flaws in the mesostructure, the bending strength of cast glass is expected to be comparable but slightly less than that of standard float glass.

Раннесредневековые иконки-привески. Образцы и подражания

Objects of personal devotion originating from archaeological excavations of ancient Russian monuments are of great importance for analyzing the history of the development of artistic thought, understanding Christian images and the ways of their distribution. Serial popular objects that evoke dimitation and served as master models for secondary castings indicate the formation and spread of the all-Russian traditions of honoring certain saints. The earliest and reliably dated icons-pendants with mounted St. George were found in Novgorod, which, perhaps, was the center from where they spread across the territory of North and West Russia, up to Latgale and Eastern Poland.Pendants with the composition “The Dormition of the Virgin Mary” on one side also belong to rather mass types of ancient Russian devotional objects. It was believed that they were associated with the Dormition Cathedral in Vladimir, erected in the middle of the 12th century by Prince Andrei Bogoliubsky. New finds of alarge series of similar medallions on the territory of Ukraine cast doubt on the existence of a single center for their production, which was located in Northeast Russia. The distribution of personal devotional objects in the Old Russian territory clearly reflects the existence of both common traditions that overcame internal and external borders, as well as local cults.

Kinetics of Phase Interaction During Secondary Cast Iron Melting

The article deals with the kinetics of phase interaction during secondary cast iron melting in cupolas and electric furnaces. The calculation of mass transfer according to the equations of electrochemical kinetics is possible only for individual cases. As the task of secondary melting of cast iron is to achieve a certain composition of cast iron, it is advisable to program complex mass transfer processes in the form of a generalized function, including the transport coefficients and the driving force of mass transfer. It is proposed to introduce the notion of the visible mass transfer coefficient (k^v), which is the density of the mass flow of an element related to one percent of the element's concentration in cast iron. The interaction of phases in devices for secondary cast iron melting is analyzed according to the laws and periods of melting. A mathematical model of mass transfer during secondary cast iron melting has been developed. Studies were conducted using a laboratory gas cupola and a 700 kg/h gas cupola, and quantitative characteristics of mass transfer have been established.

Secondary cast Al-alloys with higher content of iron

The use of secondary aluminium cast alloys can reduce significantly the production costs of a casting, are cheaper and their production requires much less energy and generates less CO2 emissions. But secondary Al-alloys (produced from Al-scrap) contain higher background Fe levels than the primary metal. The article describes the evaluation of Fe-rich phases in secondary AlSi7Mg0.3 cast alloys with amount 0.12; 0.45 and 0.65 wt. % of Fe. Higher content, as 0.3-0.5 wt. % of Fe, causes first of all formation of Fe- phases (needle-like Al5FeSi and skeleton-like Al15(FeMg)3Si2). First of all long and brittle Fe-platelets (needles as they appear in the microstructure) have influence on the formation of porosity and increase the dimensions of the casting defects. In experimental material was observed, as the iron content increases, the volume fraction of Fe-rich intermetallic phase’s increases too. A higher percentage of iron occurred to the progressive lengthening of a needle-like Fe-phase, Al15(FeMg)3Si2 phases was transformed into Al5FeSi phase; average pore sizes gently decreased, but maximal pore size increased.

Study of Bending Fatigue Properties of Al-Si Cast Alloy

AbstractFatigue properties of casting Al-alloys are very sensitive to the microstructural features of the alloy (e.g. size and morphology of the eutectic Si, secondary dendrite arm spacing - SDAS, intermetallics, grain size) and casting defects (porosity and oxides). Experimental study of bending fatigue properties of secondary cast alloys have shown that: fatigue tests up to 106-107cycles show mean fatigue limits of approx. 30-49 MPa (AlSi9Cu3 alloy - as cast state), approx. 65-76 MPa (AlSi9Cu3 alloy after solution treatment) and 60-70 MPa (self-hardened AlZn10Si8Mg alloy) in the tested casting condition; whenever large pore is present at or near the specimen’s surface, it will be the dominant cause of fatigue crack initiation; in the absence of large casting defects, the influence of microstructural features (Si morphology; Fe-rich phases) on the fatigue performance becomes more pronounced.

Microstructure and mechanical performance of a secondary cast aluminium piston alloy with minor element additions

The effect of individual and combined minor element additions (Sr, Sb, Mn, Cr and Al-5Ti-1B grain refiner) on microstructure and mechanical performance of a secondary cast aluminium piston alloy, with 1 wt-% Fe was investigated. It was observed that addition of Cr of up to 1% was better than a 0.53%Mn addition in improving tensile strength, impact energy and percent elongation of the alloy. The high mechanical performance recorded with addition of 1%Cr alloy was attributed to the significant reduction in porosity levels compared to all other minor element additions. It also resulted in a microstructure with fine compact intermetallic compounds. Other element additions also resulted in improved mechanical properties with 0.53%Mn performing better than 0.3%Mn + 0.2%Cr. Marginal improvements in mechanical performance were recorded with addition of 0.02%Sr (or 0.05%) and 0.02%Sb individually or in combination with 0.53%Mn. This was attributed to general increase in porosity and volume fraction of intermetallics.