scholarly journals SUITABILITY OF MOULDING MATERIALS FOR Al-Li ALLOY CASTING

2021 ◽  
Vol 55 (2) ◽  
pp. 311-316
Author(s):  
Bastri Zeka ◽  
Boštjan Markoli ◽  
Primož Mrvar ◽  
Jožef Medved ◽  
Mitja Petrič
Keyword(s):  
Calcium Silicate ◽  
Cast Alloy ◽  
Inert Atmosphere ◽  
Reaction Products ◽  
Sand Mixture ◽  
Alloy Casting ◽  
Gas Porosity ◽  
Casting Quality ◽  
Cast Alloys ◽  
Moulding Material

The paper describes the production of an AlSi7Mg cast alloy with Li additions and the reactions of the melt with different moulding materials. It is known that Li is very reactive and tends to form various reaction products such as oxides, gases, etc., which can influence the casting quality. The aim of the research was to find a suitable way to produce such an alloy and to describe the reaction products that are formed between the melt and the moulding material and thus to find a suitable moulding material for processing Al cast alloys with Li additions. The melt was produced in an induction furnace under an inert atmosphere. After melting, 1 w/% Li was added and the melt was cast into five different mould materials consisting of graphite, steel, a CO2 sand mixture, Croning mixture and calcium silicate materials. In the last three cases, various alcohol-based coatings were also used, such as graphite, zirconium oxide-graphite coating and aluminate-graphite filler coating. The results showed that the reaction products in the form of powder on the casting surfaces and the gas porosity in the castings occurred in the cast of a calcium silicate mould and sand mould mixtures. In the case of graphite and steel moulds, the casting surfaces were not oxidised, with no reaction products, and no gas porosity.

scholarly journals Advantages of Colour Etching in Quality Control of Recycled Al-Si Cast Alloys

2019 ◽  
Vol 1 (1) ◽  
pp. 296-303
Author(s):  
Eva Tillová ◽  
Lenka Kuchariková ◽  
Mária Chalupová ◽  
Juraj Belan ◽  
Alan Vaško ◽  
...  
Keyword(s):  
Quality Control ◽  
Cast Alloy ◽  
Structural Components ◽  
Microscopic Appearance ◽  
Structure Information ◽  
Casting Quality ◽  
Colour Contrast ◽  
New Information ◽  
Cast Alloys ◽  
Two Phases

Abstract Colour Metallography is a set of light metallographic microscopy methodologies that utilize phase colour contrast as a source of new structure information compared to conventional techniques. In many cases, colour contrast can be induced where no identifiable phase contrast is obtained by conventional techniques. With the help of colour contrast, we gain new information on the structure of Al-Si alloys, especially intermetallic phases, in which the benefits of its use in casting quality control are of benefit. Blue-yellow contrast is definitely more pronounced than dark grey or light grey contrast. There is no substantial reproducible colour reproduction, since it is irrelevant whether the two phases are distinguished by blue-yellow or green-ocher contrast. When using the colour contrast, the structural components differ not only according to their microscopic appearance, but also based on the knowledge of the chemical composition of alloys, interactions between structural components, knowledge of the possible influence of Al-alloys structure (e.g. refining, modifications, heat treatment). Colour contrast in quality control of Al-Si alloys was applied to AlSiMg cast alloy (AlSi7Mg0.3; AlSi7MgTi; AlSi10MgMn; etc.)

Influence of Substituting La with Pr on Electrochemical Characteristics of RE–Mg–Ni-Based A2B7-Type Alloys Prepared by Melt Spinning

2012 ◽  
Vol 560-561 ◽  
pp. 1011-1015
Author(s):  
Yang Huan Zhang ◽  
Tai Yang ◽  
Hong Wei Shang ◽  
Ying Cai ◽  
Hui Ping Ren ◽  
...  
Keyword(s):  
Discharge Capacity ◽  
Melt Spinning ◽  
Hydrogen Diffusion ◽  
Cast Alloy ◽  
High Rate ◽  
Limiting Current ◽  
Electrochemical Characteristics ◽  
Electrochemical Hydrogen Storage ◽  
Cast Alloys ◽  
Rate Discharge

The RE–Mg–Ni-based A2B7-type La0.75−xPrxMg0.25Ni3.2 Co0.2Al0.1 (x = 0, 0.1, 0.2, 0.3, 0.4) electrode alloys were fabricated by casting and melt spinning. The microstructures and electrochemical characteristics of the as-cast and spun alloys were investigated in detail. The results indicate that the as-cast and spun alloys have a multiphase structure, consisting of two main phases (La, Mg)2Ni7 and LaNi5 as well as a residual phase LaNi2. The substitution of Pr for La results in a notable grain refinement of the as-cast alloys without altering the phase structure of the alloys. The discharge capacity of the alloys first rises and then falls with the variation of the Pr content. As Pr content grows from 0 to 0.4, the discharge capacity increases from 389.4 (x = 0) to 392.4 (x = 0.1) and then drops to 383.7 mAh/g (x = 0.4) for the as-cast alloy. And it mounts up from 393.5 (x = 0) to 397.9 (x = 0.1) and then declines to 382.5 mAh/g for the as spun (5 m/s) alloys. Furthermore, the measurements of the electrochemical hydrogen storage kinetics reveal that the high rate discharge ability (HRD), the limiting current density (IL) and the hydrogen diffusion coefficient (D) of the alloys first increases then decreases with the rising amount of Pr substitution.

Structure and mechanical properties of cast quasicrystal-reinforced Mg–Zn–Al–Y base alloys

2004 ◽  
Vol 19 (5) ◽  
pp. 1531-1538 ◽  
Author(s):  
Guangyin Yuan ◽  
Kenji Amiya ◽  
Hidemi Kato ◽  
Akihisa Inoue
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Cast Alloy ◽  
Strengthening Mechanism ◽  
Icosahedral Quasicrystal ◽  
Compression Tests ◽  
Strengthening Phase ◽  
Creep Tests ◽  
Cast Alloys ◽  
Bulk Alloys

The structure and mechanical properties of Mg–Zn–Al–Y base cast alloys containing an icosahedral quasicrystal phase (i-phase) as a main strengthening phase were investigated. Mg–8Zn–4Al–xY base bulk alloys containing the i-phase were prepared by casting into a copper mold at moderate cooling rates. The Y addition was effective for decreasing the size of the i-phase and the increasing the homogeneity of its dispersed state. The mechanical properties examined by compression tests at room temperature were much superior to those of a conventional AZ91 Mg alloy. The creep tests at elevated temperatures indicated a promising high temperature creep resistance of the quasicrystal-reinforced Mg–Zn–Al–Y cast alloy. The strengthening mechanism was also discussed.

The Supply of Casthouse Equipment and Empowerment of Knowledge to Cast Aerospace Alloys the Almex Way

2009 ◽  
Vol 630 ◽  
pp. 205-211
Author(s):  
Shaun Hamer
Keyword(s):  
Hard Alloy ◽  
Critical Parameters ◽  
Alloy Casting ◽  
Process Route ◽  
Process Understanding ◽  
Aerospace Alloys ◽  
Cast Product ◽  
Cast Alloys ◽  
Technology Users ◽  
The Aluminum Industry

For well over a decade, Almex USA Inc. has been supplying hard alloy casting technology to the aluminum industry. Today, customers on five continents produce 2000 and 7000 series aluminum billets using this technology in sizes ranging from 75mm through to 1080mm in diameter. In order to produce such a range of sizes in hard to cast alloys and to aerospace standards, Almex has imparted complete casthouse process understanding and know-how, along with equipment supply to its customers. This paper provides an overview of Almex’s hard alloy casthouse technology and describes some of the critical parameters which must be controlled throughout the process route in order to produce defect free alloys for forging, extrusion and flat rolled applications. Explanation is also made of the microstructural requirements of the as cast product and how these influence the final product; along with the range of quality control solutions supplied by Almex to ensure these requirements are met on a continuous and repeatable basis by Almex’s technology users.

The Failure Degradation of Recycled Aluminium Alloys with High Content of β-Al5FeSi Intermetallic Phases

2020 ◽  
Vol 403 ◽  
pp. 97-102
Author(s):  
Denisa Medvecká ◽  
Lenka Kuchariková ◽  
Milan Uhríčik
Keyword(s):  
Aluminium Alloys ◽  
Cast Alloy ◽  
Intermetallic Phases ◽  
X Ray ◽  
Fracture Surfaces ◽  
Phase Lead ◽  
Micro Cracks ◽  
Fe Content ◽  
Increased Risk ◽  
Cast Alloys

In this study, the effect of the β-Al5FeSi phases on fracture surfaces in secondary AlSi7Mg0.3 cast alloys with common and higher amount of iron was investigated. Iron addition caused the formation of different Fe-rich intermetallic phases in aluminium alloys. Components made of secondary aluminium alloys commonly have a higher amount of such phases. Sharp needles as β-Al5FeSi phase lead to initiate stress tension, thereby contributing to increased risk of micro-cracks formation on the fracture surfaces. To determine the effect of β-Al5FeSi to fracture surfaces of AlSi7Mg0.3 cast alloy, SEM microscopy with energy-dispersive X-ray spectroscopy (EDX) was used to study the amount of needles phases, their morphology and violation wave. It was found that increasing Fe content increased the size and the number of Al5FeSi phases. The fractographic analysis of fracture surfaces shows an increasing amount of cleavage fracture in materials with a higher amount of iron, too.

Effect of Warm Deforming and Heat Treating on Microstructure and Mechanical Properties of Mg-Zn-Zr Magnesium Alloy

2012 ◽  
Vol 472-475 ◽  
pp. 707-711
Author(s):  
Guan Lu ◽  
Ya Qin Yang ◽  
Bao Cheng Li ◽  
Zhi Min Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cast Alloy ◽  
Hot Extrusion ◽  
Heat Treating ◽  
Optical Microscope ◽  
Tensile Fracture ◽  
Strengthening Effect ◽  
Zk60 Alloy ◽  
Cast Alloys

In this paper, the effects of hot extrusion and T5、T6 heat treatment on the microstructures and mechanical properties of ZK60 magnesium alloys are investigated by optical microscope, electronic scanning microscope and mechanical testers. The result shows that both the tensile strength and the elongation of the ZK60 alloy extruded at 380°Care much higher than that of the as-cast alloys, as there are much granular second phases precipitated during the extrusion. The tensile strength of the extruded and T5 treated alloy increases while the elongation decreases faster than that of the extruded alloy. The strengthening effect of the T6 treatment is inferior to that of the T5 treatment. The tensile fracture of the as-cast alloy is brittle fractured while that of the extruded and T5 treated alloy is ductile fractured with lots of deep and even dimples.

A357 Aluminium Cast Alloys for Extrusion Processes

2012 ◽  
Vol 192-193 ◽  
pp. 454-459 ◽  
Author(s):  
Manel Campillo ◽  
M. Teresa Baile ◽  
Sergi Menargues ◽  
Enric Martín ◽  
Antonio Forn
Keyword(s):  
Cast Alloy ◽  
Hot Extrusion ◽  
Extrusion Speed ◽  
Friction Forces ◽  
Automotive Components ◽  
The Press ◽  
Extruded Product ◽  
Cast Production ◽  
Cast Alloys ◽  
Semi Solid

The A357 Al-Si-Mg cast alloy is commonly used for cast production of automotive components in conventional HPDC and in semi-solid processes. The aim of this work is to study the application of A357 cast alloy in thixoextrusion processes. This technology offers new possibilities of application for cast alloys and several advantages in from of conventional processes of hot-extrusion: lower pressure, minor friction forces, higher material fluidity and longer tool life. The thixoextrusion was experimented in a pilot plant, at different speeds and temperatures, with an induction furnace and a 400 Tn press. With ingots of A357 as cast, a tool with a ratio of 8.5 and with temperatures of extrusion around 560 °C, it is possible to obtain extrusion speeds more than 3 m•s-1. In all cases, when the speed of extrusion increases, the press of extrusion decreases. The effect of heat treatments and extrusion speed in the microstructure of the extruded product is evaluated.

scholarly journals Copper (II) Mediated Oxidative Alkoxylation of White Phosphorus. Communication 1.

2010 ◽  
Vol 12 (3,4) ◽  
pp. 259
Author(s):  
R.R. Abdreimova ◽  
F.Kh. Faizova ◽  
A.A. Karimova
Keyword(s):  
Metal Ion ◽  
Phosphorous Acid ◽  
Inert Atmosphere ◽  
White Phosphorus ◽  
Main Reaction ◽  
Reaction Products ◽  
Dimethyl Phosphite ◽  
Trialkyl Phosphates ◽  
Oxidative Alkoxylation ◽  
Kinetics Of

White phosphorus has been oxidized by copper (II) acetylacetonate, halides or carboxylates in aliphatic alcohols to yield dialkyl phosphates and trialkyl phosphates under inert atmosphere and mild reaction conditions. Trialkyl phosphite has been observed as unstable organophosphorus intermediate, which is being converted into the main reaction products. In the case of methanolic solutions, the derivatives of two step acidolysis of dimethyl phosphite, monomethyl phosphite and phosphorous acid, have been additionally detected among the reaction products. The influence of the copper (II) oxidants on the kinetics of accumulation and transmutation of organophosphorus products has been explored. The order of oxidative ability of the copper (II) compounds has been established. The major steps of the reaction including (i) the coordination of white phosphorus and alcohol to metal ion and (ii) the redox decomposition of this intermediate complex accompanied by reducing elimination of elementary copper and formation of organophosphorus product have been also suggested.

scholarly journals Study of the precipitation hardening process in recycled Al-Si-Cu cast alloys

2017 ◽  
Vol 62 (1) ◽  
pp. 397-403 ◽  
Author(s):  
L. Kuchariková ◽  
E. Tillová ◽  
M. Matvija ◽  
J. Belan ◽  
M. Chalupová
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Precipitation Hardening ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Second Phase ◽  
Thin Foils ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Cast Alloys

AbstractThe formation of extremely small uniformly dispersed particles of a second phase within the original phase matrix during heat treatment changed material properties. Therefore the characterization of precipitation had been investigated using high resolution transmission electron microscopy (TEM) and electron diffraction of thin foils for an AlSi9Cu3 cast alloy. For investigation the hardening effect onto mechanical properties of aluminium cast was used heat treatment, which consisted from solution treatment at 515°C / 4 hours (h), followed by quenching into water with temperature 50°C and artificial aging using different temperatures 170°C and 190°C with different holding time 2, 4, 8, 16, and 32 hours. The observations of microstructure and substructure reveals that precipitation hardening has caused great changes in size, morphology and distributions of structural components, the formation of precipitates of Cu phases, and the change of mechanical properties as well.

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