The capability enhancement of aluminium casting process by application of the novel CRIMSON method

The conventional foundry not only frequently uses batch melting, where the aluminium alloys are melted and held in a furnace for long time, sometimes as long as a complete shift, but also uses the gravity sand casting process where the molten aluminium alloys are transferred using a ladle from furnace to pour station and are poured into a mould. During the filling of the mould, the turbulent nature of the liquid metal gives rise to massive entrainment of the surface oxide films which are the subsequently trapped into the liquid and act as micro cracks. Also the long exposure time of the liquid surface to the surrounding environment during melting, transferring and filling will increase the level of hydrogen absorption from the atmosphere. The abovementioned factors are often the main reasons for casting defect generation. In this paper the novel CRIMSON aluminium casting method is introduced which has a number of advantages. Instead of gravity filling method, it uses the single shot upcasting method to realize the rapid melting and rapid counter-gravity-filling mould operations which reduce the contact time between the melt and environment thus reducing the possibility of defect generation. Another advantage is the drastic reduction of energy consumption due to shortened melting and filling time. A simulation software, FLOW-3D, is used to compare this new method with the conventional gravity casting process. A tensile bar case is used as a sample to simulate the filling process

The improvement of aluminium casting process control by application of the new CRIMSON process

All The traditional foundry usually not only uses batch melting where the aluminium alloys are melted and held in a furnace for long time, but also uses the gravity filling method in both Sand Casting Process (SCP) and Investment Casting Process (ICP). In the gravity filling operation, the turbulent behaviour of the liquid metal causes substantial entrainment of the surface oxide films which are subsequently trapped into the liquid and generate micro cracks and casting defects. In this paper a new CRIMSON process is introduced which features instead of gravity filling method, using the single shot up-casting method to realize the rapid melting and rapid filling mould operations which reduce the contact time between the melt and environment thus reducing the possibility of defect generation. Another advantage of the new process is the drastic reduction of energy consumption due to shortened melting and filling time. Two types of casting samples from SCP and ICP were compared with the new process. The commercial software was used to simulate the filling and solidification processes of the casting samples. The results show that the new process has a more improved behaviour during filling a mould and solidification than the two conventional casting processes

Improvements in energy consumption and environmental impact by novel single shot melting process for casting

The CRIMSON (Constrained Rapid Induction Melting Single Shot Up-Casting) method uses a rapid induction furnace to melt just enough metal for a single mould rather than bulk melting used in traditional casting process. The molten metal is then transferred to a computer – controlled platform to complete the counter-gravity up filling. The highly controlled metal flow is pushed into the mould to finish the pouring and solidification. In the present paper the energy saving capability of CRIMSON approach is compared with conventional sand casting process. The paper focuses on the energy and resource efficiency optimization of casting stages through simulation and life cycle assessment analysis simulation for proposing alternative means for the better performance of such processes. It is proven that the CRIMSON process can produce high quality castings with higher energy efficiency and lower environmental impact

The challenges for energy efficient casting processes

Casting is one of the oldest, most challenging and energy intensive manufacturing processes. A typical modern casting process contains six different stages, which are classified as melting, alloying, moulding, pouring, solidification and finishing respectively. At each stage, high level and precision of process control is required. The energy efficiency of casting process can be improved by using novel alterations, such as the Constrained Rapid Induction Melting Single Shot Up-casting process. Within the present study the energy consumption of casting processes is analyzed and areas were great savings can be achieved are discussed. Lean thinking is used to identify waste and to analyse the energy saving potential for casting industry

Simulation based energy and resource efficient casting process chain selection: a case study

Casting processes are among the most energy intensive manufacturing processes. A typical modern casting process contains different stages, classified as melting-alloying, moulding, pouring, solidification, fettling, machining and finishing respectively. At each stage, large amounts of energy are consumed. Since a number of different casting processes exist, it is not always straightforward which process chain to select among the available ones. Up to now the selection is based on cost criteria. This paper focuses on the different criteria that needs to be considered and how they can be simulated focusing especially on the energy and resource efficiency of casting stages. A disruptive technology that uses a rapid induction furnace to melt just enough metal for a single mould rather than bulk melting used in traditional processing is proposed and validated

Validation of Energy Saving Novel Single Shot Melting Process for Foundry Industry

Casting is a metal forming process: Pouring the melt metal into a desired shaped mould wait it solidifies. It is often used to manufacture complex parts, which are too expensive or time consuming to produce by other methods. However, casting probably is one of the most challenging manufacturing process. It is a highly technical engineering process requiring deep scientific understanding. A typical modern casting process contains six different stages, which named as melting, alloying, moulding, pouring, solidification and finishing respectively. At each stage, high level and precision of process control is required. Casting process also is one of the most energy intensive manufacturing processes. The metal melting consumes over half of the energy in a casting process. Therefore, the expenses on the casting process has been a significant concern due to the rising of the energy prices. A new casting process, CRIMSON (Constrained Rapid Induction Melting Single Shot Up-casting), has been developed by teams from Cranfield University and the N-TEC Ltd. It can improve the energy efficiency of a casting process without reducing the quality. The process, firstly, uses the rapid induction furnace to melt just enough metal for one single casting; then transfer the molten charge to a computer controlled counter gravity casting platform. Finally, the highly controlled metal flow is pushed into the mould to finish the pouring and solidification. Such process reduces the defect generation and energy consumption by rapid melting, minimum holding and smooth filling of the mould. Since the CRIMSON process is a relatively new casting production process. The main objective of this dissertation is to validate the CRIMSON process by different approaches. Firstly, the concept of the sound casting running system design and the principle of the novel CRIMSON process has been introduced. Secondly, Flow3D (A comprehensive, general-purpose computational fluid dynamics software) has been used to investigate the filling patterns of the novel CRIMSON process and the gravity sand casting process. Thirdly, life cycle assessment (LCA) method has been used in this project to review the energy consumption of the conventional casting sector and the novel CRIMSON process. The inventory data was used to assess the environmental impacts of the both casting processes. Moreover, this project investigated the productivity of the CRIMSON process. The productivity of the CRIMSON process for certain range of the casting product has been investigated and compared with the conventional casting process. Finally, the cost of the CRIMSON process has been estimated. The total variable cost of the CRIMSON process was investigated and compared with the conventional casting process as well. Key conclusions can be addressed as below: Because of the geometry requirement, the gravity poured running system cannot avoid generating double oxide film defect during the filling. For the CRIMSON process, all the important parameters (such as temperature, time, and velocity) are under control. The piston only needs to move at low speed to guarantee the liquid metal is delivered smoothly and the double oxide films are not formed or entrapped. The material flow and the embedded energy of the casting making can be evaluated by the lift cycle inventory data collection method. The embedded energy of the sand casting is about 55 MJ/kg. However, to consider the recycling and reusing the internal material, the energy burden of the CRIMSON and the conventional sand casting are 16 MJ/kg and 18 MJ/kg respectively. Considering the energy burden for saleable casting, the CRIMSON process consumes 230 MJ/kg to make saleable casting; the conventional process consumes 449 MJ/kg to make saleable casting. By using the collected inventory data, the environmental impact assessment can be carried out for both the casting process. The results indicate that the CRIMSON process is environmental friendly compared with the conventional sand casting process. A complete foundry model was developed in order to investigate the productivity of the CRIMSON process. The WITNESS simulation tool was used to assess the productivity investigation. For casting size less than 2 kg, the conventional sand casting process is productive. However, as the casting size increases, the CRIMSON process becomes more productive. Cost estimation also carried out for the CRIMSON process. The total variable cost of the casting process was investigated. It was found that the most expensive variable cost is the raw material cost, which can be 80% of the total variable cost. Furthermore, it is concluded that the CRIMSON process has less variable cost compared with the conventional sand casting process under most of the circumstances

Comparison of the environmental impact of the CRIMSON process with normal sand casting process

The CRIMSON process is an alternative process to conventional casting that can be used for small to medium batch sizes. The aim of this process are to improve the casting quality and reduce the energy consumption within light-metal casting industry. Nowadays, the energy efficiency becomes more and more important. This is not only about the cost of the production, but also about the environmental effect. In this paper, the CRIMSON process will be compared with the conventional sand casting process. The Life cycle assessment (LCA) method will be used to assess the environmental impact of both casting processes

Reduction of Energy Consumption and GHGs Emission in Conventional Sand Casting Process by Application of a New CRIMSON Process

In conventional foundry, engineers generally consider the quality of casting part as the most essential issue and regard the energy consumption and Green House Gas (GHGs) emission as the auxiliary ones. This usually causes large amount of energy consumption as a result of the inefficient casting processes used and increases the production costs and environmental pollution. This paper presents the new CRIMSON process where its facility and melting process were compared with conventional melt furnaces and aluminium alloy melting process. An actual case was investigated to reveal quantitatively how the conventional foundry wastes energy and increases GHGs emission, and what the improvement of energy efficiency and the GHGs emission reduction can be achieved using the new CRIMSON process. The results of this investigation will help the foundry engineer recognize the importance of energy saving and environmental protection and show how to utilise this new process to reduce production costs and carbon footprint without decreasing the quality of the cast part

Investigating the energy consumption of casting process by multiple life cycle method

The Constrained Rapid Induction Melting Single Shot Up-Casting (CRIMSON) process is an alternative casting process to conventional casting that can be used for small to medium batch production. The aim of the process is to improve the casting quality and reduce the energy consumption within light-metal casting industry. Multiple life cycle method was used in this paper to investigate the energy consumption of the casting process. From the investigation, it was shown that energy consumption of the casting production is influenced by the Operational Material Efficiency (OME): the higher the OME the lower energy consumption of the casting production. It is concluded that the CRIMSON Process only use 23% of energy compared with conventional method for the same casting production. By adopting the CRIMSON method, 130 GJ/tonne of energy can be saved for aluminium casting production