Permanent Mold Research Articles

Microstructure and Phase Formation of Novel Al80Mg5Sn5Zn5X5 Light-Weight Complex Concentrated Aluminum Alloys

In this work, three novel complex concentrated aluminum alloys were developed. To investigate the unexplored region of the multicomponent phase diagrams, thermo-physical parameters and the CALPHAD method were used to understand the phase formation of the Al80Mg5Sn5Zn5Ni5, Al80Mg5Sn5Zn5Mn5, and Al80Mg5Sn5Zn5Ti5 alloys. The ingots of the alloys were manufactured by a gravity permanent mold casting process, avoiding the use of expensive, dangerous, or scarce alloying elements. The microstructural evolution as a function of the variable element (Ni, Mn, or Ti) was studied by means of different microstructural characterization techniques. The hardness and compressive strength of the as-cast alloys at room temperature were studied and correlated with the previously characterized microstructures. All the alloys showed multiphase microstructures with major α-Al dendritic matrix reinforced with secondary phases. In terms of mechanical properties, the developed alloys exhibited a high compression yield strength up to 420 MPa, high compression fracture strength up to 563 MPa, and elongation greater than 12%.

Mould design optimisation by FEM

Production can be briefly defined as creating something new as a result of effort. There are many different production methods. With the industrial revolutions, the number of these methods has increased, and these methods have developed. Over time, heavy and laborious work that people had to do began to be done by machines. The casting method, which is one of the most common production methods in the world, is to pour the molten metal or its alloy into a mould cavity suitable for the shape of the desired product and remove it from the mould after it solidifies. In this study, firstly, the manufacturing method by casting was mentioned, and the difficulties of mould design in the casting method were explained. Secondly, the benefits of computer-aided simulation programs for casting are explained. As an example, a model was designed and different runners were added to this model. These models, which were prepared afterwards, were cast in a virtual environment with the FLOW-3D CAST program, which is a simulation program. Casting results and casting defects after these castings were compared and interpreted. The results show that it is important for the casting quality to keep the runner diameters as small as possible in runner designs. Two or three times more air voids are formed in the sand mould casting method compared to the permanent mould casting. Additionally, it was observed that the casting material had less shrinkage in the sand mould casting method. It is concluded that sand mould casting is disadvantageous in terms of the parameter of time.

The Structure of Al – Mg – Si Casting alloys Modified by Lithium and Scandium

The structure of hypoeutectic Al – Mg – Si alloys cast in permanent mold, as well as using a high-pressure die-casting unit (HPDC), was investigated. Changes in the structure after additional alloying of the base alloy (Al – 5.5Mg – 2.5Si – 0.6Mn) with lithium and scandium were studied. For a more detailed description of the structure of the alloys, phase diagrams and the volume fractions of the phases in the Thermo-Calc software were calculated. Thermo-Calc results are in good agreement with metallographic studies. The microstructure of the alloys was investigated using a scanning electron microscope (SEM) on polished and deeply etched microsections. The article also shows the strong influence of the crystallization rate on the eutectic morphology and the secondary dendrite arm spacing (SDAS). Alloying the base alloy with lithium leads to a change in the eutectic morphology from lamellar to fine fibrous. Alloying with scandium not only changes the eutectic morphology from lamellar to the fine fibrous but also reduces the SDAS. Scandium addition leads to the formation of primary Al3Sc crystals, which act as a substrate for the heterogeneous nucleation of α-Al dendrites and Al – Mg2Si eutectic. To determine the effect of alloying elements on the properties of alloys, hardness, tensile strength, and elongation were measured. Local mechanical properties were measured as microhardness of α-Al dendrites, Al – Mg2Si eutectic, and Al3Sc phase. Alloys with lithium and scandium show increased properties in the cast state compared to the base alloy.

Effect of Al Content on Microstructure Evolution and Mechanical Properties of As-Cast Mg-11Gd-2Y-1Zn Alloy.

In the present paper, the Mg-11Gd-2Y-1Zn alloys with different Al addition were fabricated by the gravity permanent mold method. The effect of Al content on microstructure evolution and mechanical properties of as-cast Mg-11Gd-2Y-1Zn alloy was studied by metallographic microscope, scanning electron microscope, XRD and tensile testing. The experimental results showed that the microstructure of as-cast Mg-11Gd-2Y-1Zn alloy consisted of α-Mg phase and island-shaped Mg3 (RE, Zn) phase. When Al element was added, Al2RE phase and lamellar Mg12REZn (LPSO) phase were formed in the Mg-11Gd-2Y-1Zn alloy. With increasing Al content, LPSO phase and Mg3 (RE, Zn) phase gradually decreased, while Al2RE phase gradually increased. There were only α-Mg and Al2RE phases in the Mg-11Gd-2Y-1Zn-5Al alloy. With the increase of Al content, the grain size decreased firstly and then increased. When the Al content was 1 wt.%, the grain size of the alloy was the minimum value (28.9 μm). The ultimate tensile strength and elongation increased firstly and then decreased with increasing Al addition. And the fracture mode changed from intergranular fracture to transgranular fracture with increasing addition. When Al addition was 1 wt.%, the maximum ultimate tensile strength reached 225.6 MPa, and the elongation was 7.8%. When the content of Al element was 3 wt.%, the maximum elongation reached 10.2% and the ultimate tensile strength was 207.7 MPa.

Effects of Eu modification and heat treatment on microstructure and mechanical properties of hypereutectic Al–Mg2Si composites

To modify the coarse primary Mg2Si phase and improve mechanical properties of Mg2Si reinforced aluminum matrix composites, hypereutectic Al–18Mg2Si composites with different Eu contents were fabricated by permanent mold casting and extrusion followed by heat treatment. Results show that the as-cast Al–18Mg2Si composites consisted of primary Mg2Si and eutectic structure (Al + Mg2Si). Eu addition can obviously modify the primary Mg2Si morphology from dendrite to flat truncated octahedron shape, and the average size also decreased from ∼90 μm to ∼16 μm with increasing Eu content from 0 to 0.1%. But further increasing Eu content would cause over-modification. After T6 treatment, sharp corners of primary Mg2Si were spheroidized and the average size of primary Mg2Si were further decreased. DTA result shows the nucleation temperature of primary Mg2Si increased by Eu addition. Al2Si2Eu phase can act as the heterogeneous nucleation substrate for the primary Mg2Si phase and thus refine the size of primary Mg2Si particle. TEM results show the segregation and/or selective adsorption of Eu on the {100} facets of primary Mg2Si suppress the growth of primary Mg2Si, and thus refine and modify the composites, which proposed to the dominant reason for the refinement and modification of the primary Mg2Si phase. Tensile tests show that the mechanical properties enhanced with increasing Eu content. The elongation and ultimate tensile strength of the T6-treated Al–18Mg2Si-0.1Eu composite improved to 5.2% and 241 MPa, which enhanced 225% and 91% compared to the unmodified as-cast Al–18%Mg2Si composite. It is concluded that the morphology transition of primary Mg2Si from dendrite to tetrakaidecahedron and the refinement of primary Mg2Si size with Eu modification, the passivation of the sharp corners in primary Mg2Si particles as well as the appearance of β" precipitates all contribute to the improvement of the mechanical properties of the T6-treated Al–18Mg2Si composites.

EFFECT OF COOLING RATE ON MICROSTRUCTURE AND HARDNESS IN GRAY CAST IRON CASTING PROCESS

This study aims to investigate the thermal conditions of the molds, changes in microstructure and hardness of casting products using sand mold and permanent mold. The use of sand mold and permanent mold results in different cooling rates. Thermal analysis was performed using a thermocouple to obtain a temperature versus time curve. Metallographic observations were carried out using a Scanning Electron Microscope equipped with Energy-Dispersive X-ray Spectroscopy. The Vickers hardness test was carried out in three areas with different thicknesses. The results showed a constant temperature at 691 oC where the eutectoid phase reaction occurred. Testing with sand mold showed that cast iron with flake graphite was finer and spreader than graphite in cast iron produced by permanent mold. Meanwhile, gray cast iron from a casting process with a permanent mold has a higher hardness than gray cast iron from a casting process using a sand mold.

RAFFMETAL EN AB-Al Si7Mg0.3 (EN AB-42100)

Abstract Raffmetal EN AB-Al Si7Mg0.3 (EN AB-42100) is a heat-treatable, Al-Si-Mg casting alloy in ingot form for remelting. It is used extensively for producing sand, permanent mold and investment castings for applications requiring a combination of excellent casting characteristics, high strength with good elongation, and good corrosion resistance. This alloy can be produced to a wide range of mechanical properties by making small adjustments to the magnesium content and/or heat treatment. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-480. Producer or source: Raffmetal S.p.A.

Influence of Cooling Conditions on Long-Period Stacking-Ordered Phase Evolution and Corrosion Behavior of As-Cast Resoloy®

This study focuses on the influence of cooling conditions on the long-period stacking-ordered (LPSO) phase evolution and corrosion behavior of as-cast Resoloy®, a bioresorbable Mg-Dy-based alloy. Metallographic and corrosive tests are used to monitor the changes in the properties of this material. The corrosion behavior is investigated by potentiodynamic polarisation. Permanent mold chill casted ingots are wire-eroded to cylindrical platelets. The eroded platelets are solution heat treated over three different time periods. Cooling is performed in two different ways: quenching in water and cooling in air at ambient temperature. The as-cast condition shows a homogeneous fine-grained microstructure. Grains become larger with increasing heat treatment duration and slow cooling leads to additional grain growth. Furthermore, cooling in air leads to faint lamellar LPSO structures, which develop from bulk LPSO structures during the cooling process. The corrosion rate of the cooled platelets increases with increasing grain size. When the lamellar LPSO structures are uniformly distributed over the entire grain, the corrosion starts at the matrix between the LPSO lamellae and stops at them. Heat treatment at 500 °C reduces the normal potential difference between matrix and secondary phase and thus weakens the galvanic corrosion.

Farklı Soğutma Kanallarına Bir Kokil Kalıp Çekirdeğinin Termal Davranışlarının Nümerik Olarak İncelenmesi

Bu çalışmada, farklı soğutma kanallarına sahip bir kokil kalıp çekirdeği nümerik olarak incelenmiştir. Klasik soğutma kanallı kalıp çekirdeği, kanatlı soğutma kanallı kalıp çekirdeği ve dalgalı soğutma kanallı kalıp çekirdeğinin 3D-CAD çizimleri yapılmıştır. Elde edilen tasarımların termal davranışları Fluent yazılımı kullanılarak analiz edilmiştir. Soğutma performanslarının karşılaştırılması amacıyla, klasik, kanatlı ve dalgalı soğutma kanallı kalıp çekirdeklerinin termal davranışları nümerik olarak incelenmiştir. Erimiş metalin (Al6061 alüminyum alaşımı) kalıba dökülmesinden itibaren kalıp iç yüzeyinden 0-5. s zaman aralığında ve 0.5 s zaman adımlarıyla alınan verilerle kalıp çekirdeklerinden elde edilen ürünün (supap) sıcaklık dağılımı, katılaşma oranları karşılaştırmalı olarak irdelenmiştir. Soğutma performans sonuçlarının karşılaştırılmasından, supap sap kısmında kanatlı soğutma kanallı kalıp çekirdeğinin, supap baş kısmında dalgalı soğutma kanallı kalıp çekirdeğinin soğutma performansının daha iyi olduğu gözlemlenmiştir.

Evaluating the Application of Heating Conductor Surfaces Inside Plasma Sprayed Coatings in Permanent Mold Metal Casting Processes for Local, Near-Surface Heat Release

With casting being a complex process which involves several physical effects and interactions, a wide array of means for influencing such processes exist. Here, the liquid–solid phase change is of utmost importance, as it is a deciding factor for a part’s final properties. Especially with today’s high critical material property requirements, control of the solidification process is indispensable. For the most part, the cooling of a casting defines its solidification. What determines the cooling process is the heat balance of the system. The foundry industry has been using different approaches for influencing the heat balance for a long time. The application of different kinds of coatings with either insulating or heat transfer promoting properties as well as temperature control via cooling channels inside the mold is widely used. Progress in the field of plasma spraying of coatings and the application of heating conductor surfaces have rendered a new concept possible: The integration of heating conductors inside a coating allows for the release of heat in closest vicinity of the melt–mold interface. This paper depicts the use of numerical simulations to investigate the local application of heating conductor layers inside the mold surface coating for a permanent mold casting process and discusses concepts for influencing the heat balance that would not be possible with state-of-the-art cooling channel approaches.

Influence of Mg addition and T6 heat treatment on microstructure, mechanical and tribological properties of Al–12Si–3Cu based alloy

The aim of the present study was to investigate the influence of Mg addition and T6 heat treatment on microstructure, mechanical and tribological properties of the Al–Si–Cu–Mg alloys. In this context, a series of Al–12Si–3Cu–(0.5–2.5)Mg (wt.%) alloys were produced by permanent mould casting, and then subjected to T6 treatment. Their microstructure and mechanical properties were investigated using OM, XRD, SEM, EDS along with hardness, tension, compression and Charpy impact tests. Dry sliding friction and wear properties of the alloys were studied using a ball-on-disk type tester. It was observed that the microstructure of as-cast Al–12Si–3Cu–Mg alloys consisted of α(Al), Si, θ-CuAl2, β-Mg2Si, Q-Al5Mg8Cu2Si6 and π-Al8Mg3FeSi6 phases. T6 heat treatment gave rise to nearly spherodization of eutectic Si particles, formation of finer θ-CuAl2 and β-Mg2Si precipitates and elimination of Chinese script morphology of β-Mg2Si phase. The addition of Mg up to 2.5 wt.% decreased the hardness, tensile and compressive strengths, tensile elongation and impact toughness of the as-cast and T6-treated alloys and increased their friction coefficient and volume loss. T6 treatment, on the other hand, led to a significant increase in mechanical properties and wear resistance of as-cast alloys.

RIO TINTO 354.2

Abstract Rio Tinto 354.2 is a heat-treatable, aluminum-silicon-copper-magnesium casting alloy (3xx.x series). It is available in the form of ingots for remelting to be used for the production of sand and permanent mold castings. Alloy 354.0 was developed especially for premium engineered casting applications requiring high strength and elongation, and sound castings. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting and heat treating. Filing Code: Al-479. Producer or source: Rio Tinto Limited.

Study of the Properties of C92900 Bronze Obtained by Permanent Mold Casting, Upward Casting, and Hot Extrusion

Study of the Properties of C92900 Bronze Obtained by Permanent Mold Casting, Upward Casting, and Hot Extrusion

Modeling of cooling and heat conduction in permanent mold casting process

Motivated by the need to understand the heat transfer process in permanent mold casting, the heat conduction problem in the casting and the mold is modeled as transient one-dimensional heat flow in a double-layer cylinder with radial interfacial heat flux to emulate the cooling process of the casting. The cylinder is cooled down by dissipating heat to surrounding by convection. Green's function method, which obtained by separation of variables technique, is used to obtain a closed form solution of temperature distribution. The results of the derived analytical expressions are verified with numerical results of finite-element analysisand the published experimental results. The simulations are performed for different casting/mold materials with diversified thermo-physical properties to figure out the relationship between those properties and heat transfer process. The analytical results are justified by their good agreement with both of numerical and experimental results and its time efficiency in computation which offers advantages in potential real-time application to casting process monitoring. The mean absolute percentage error between the obtained temperatures using the developed analytical model and the measured ones was 14.5% and 2.4% for the casting and mold, respectively.

Investigation of C92900 bronze properties obtained by permanent mold casting, continuous upcasting and hot extrusion

In mechanical engineering, the antifriction tin bronzes, and C92900 bronze for instance are used for parts subjected to wear. The permanent mold casting into steel molds are commonly used to produce parts from C92900 bronze. This work investigates the possibility of C92900 bronze rods production by hot extrusion and upcasting methods. It has been discovered the hot extrusion temperature and ram speed, as well as the casting speed for upcasting that promote no defects in rods. It has been shown that hot extrusion leads to severe grain refinement up to 1.7 gm, and when casting upwards, on the contrary, an increase in the grain size occurs in comparison with the permanent mold casting. After hot extrusion and upcasting, the crystals of the Y-Cu3Sn intermetallic phase are refined in the bronze microstructure. At the same time, large agglomerations of (Pb) particles can be observed in the extruded bronze microstructure, which leads to a decrease in the coefficient of friction. The maximum hardness and tensile strength were obtained for rods produced by hot extrusion at 600 °C, and the highest elongation in rods obtained by the upcasting method. Tribological studies were carried out according to the «shaft — partial insert» scheme in a kerosene medium with a steel counter body showed that hot extrusion leads to a tenfold increase in wear resistance and a threefold decrease in the friction coefficient in comparison with rods obtained by permanent mold casting. At the same time, for the rods obtained by the upcast method, on the contrary, a decrease in wear resistance is observed. In connection with the mentioned results, it is possible to recommend the hot extrusion method for producing C92900 bronze rods in addition with casting technique.

A Numerical and Experimental Investigation of the Thermal Behavior of a Permanent Metal Mold with a Conventional Cooling Channel and a New Cooling Channel Design

A Numerical and Experimental Investigation of the Thermal Behavior of a Permanent Metal Mold with a Conventional Cooling Channel and a New Cooling Channel Design

Design and Process Analysis of Single Cavity Injection Molding Die for Plastic Wing Nut

Material selection is an important step under active planning phase in production planning and control and, so is process selection. Polymers are preferable option for various products due to their desirable properties. Light weight, low cost, corrosion resistant and high strength to weight ratio is few among them. In similar manner injection molding is the most suitable process to be preferred for processing various grades of thermoplastics. The process preferably utilizes a heating unit to take polymers to their injection temperature, a permanent mold with shaped cavity as the shape of the required product along with clamping and cooling provisions. The process is best suitable for mass production of plastic parts and is widely used industrially. The permanent mold used in injection molding process is also referred as plastic mold. These molds must be designed and analyzed before their manufacturing to ensure suitability of the molding with particular plastic material type. This article attempts to ensure suitability of molding plastic wing nuts, an internal threaded component, by injection molding process with polypropylene (PP) and high density poly ethylene (HDPE) material. Modeling of parts is done with UG Nx 9.0 while the flow analysis is performed by Autodesk Mold Flow Adviser 2015. Index Terms: Injection molding, permanent mold, internal threaded component, polypropylene, high density poly ethylene.

Prediction of grain structure in direct-chill cast Al–Zn–Mg–Cu billets using cellular automaton-finite element method

A cellular automaton-finite element (CA-FE) model was used to predict the solidification grain structure of permanent mold cast A7086 alloy. In this model, a Gaussian distribution of nucleation sites was adopted, and the Kurz-Giovanola-Trivedi model was extended to a multicomponent Al–Zn–Mg–Cu alloy system to determine the growth kinetics of the dendrite tip. For describing the Gaussian distribution of nucleation sites on the mold surface, an empirical relationship between the initial cooling rate of the melt and the nucleation density was proposed. Under various casting conditions, the calculated grain structures agreed well with the experimental results. Subsequently, the model was applied to the direct-chill (DC) cast billets, and the simulated grain structures reproduced well the experimental results. This confirmed that the current CA-FE model can be used practically and effectively in DC casting processes.

Variation in the microstructure and mechanical properties of permanent mold cast Al–3Li–2Mg–0.1Zr alloy with Zn addition

Variation in the microstructure and mechanical properties of permanent mold cast Al–3Li–2Mg–0.1Zr alloy with Zn addition

Modelling the Effect of Cu Content on the Microstructure and Vickers Microhardness of Sn-9Zn Binary Eutectic Alloy Using an Artificial Neural Network

The present study aims to clarify the impact of Cu addition and aging conditions on the microstructure development and mechanical properties of Sn-9Zn binary eutectic alloy. The Sn-9Zn alloys with varying Cu content (0, 1, 2, 3, and 4 wt.%) were fabricated by permanent mold casting. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were utilized to investigate the influence of Cu concentration on the microstructure of pre-aged Sn-9Zn-Cu alloys. The main phases are the primary β-Sn phase, eutectic α-Zn/β-Sn phases, and γ-Cu5Zn8/η-Cu6Sn5/ε-Cu3Sn intermetallic compounds. Vickers microhardness values of Sn-9Zn alloys increased with additions of 1 and 2 wt.% Cu. When the concentration of Cu exceeds 2 wt.%, the values of microhardness declined. Besides, the increase in the aging temperature caused a decrease in the microhardness values for all the investigated alloys. The variations in the microhardness values with Cu content and/or aging temperature were interpreted on the basis of development, growth, and dissolution of formed phases. The alterations of the lattice strain, dislocation density, average crystallite size, and stacking fault probability were evaluated from the XRD profiles of the investigated alloys. Their changes with Cu content and/or aging temperature agree well with the Vickers hardness results. An artificial neural network (ANN) model was employed to simulate and predict the Vickers microhardness of the present alloys. To check the adequacy of the ANN model, the calculated results were compared with experimental data. The results confirm the high ability of the ANN model for simulating and predicting the Vickers microhardness profile for the investigated alloys. Moreover, an equation describing the experimental results was obtained mathematically depending on the ANN model.