China
Africa
Explore chapters and articles related to this topic
Engineering design
Published in Alan Darbyshire, Charles Gibson, Mechanical Engineering, 2023
Alan Darbyshire, Charles Gibson
Liquid forming processes include the sand casting and die casting of metals and the injection moulding of polymer materials. The choice of process is affected by the melting point, expansivity and fluidity of a material. High melting point metals such as cast iron are generally cast in sand moulds or ceramic moulds made by the investment or ‘lost wax’ technique. Die casting is generally used with lower melting point metals such as aluminium-, magnesium- and zinc-based alloys.
Motor Frame Design
Published in Wei Tong, Mechanical Design and Manufacturing of Electric Motors, 2022
Die casting is a manufacturing casting process that can produce geometrically complex metal parts using reusable molds (i.e., dies). There is a traditional high-pressure die casting process but also using low pressures. The casting materials typically are nonferrous alloys such as aluminum, zinc, magnesium, and copper. In a die casting process, molten metal is injected under high pressure over a very short period of time into a hardened steel or cast iron die (Figure 5.4). Then, the ejection die is removed, and the die casting part is ejected by means of ejection pins. The total cycle time is very short, typically between a few seconds to less than a minute. High casting pressures help reduce porosities in casting parts, increase casting uniformity, and improve the surface finish and dimensional accuracy. Because die casting can provide good surface finishing and dimensional accuracy, only light machining is required to enforce the accuracy of a few critical dimensions. In some cases, post machining can be completely eliminated. A key feature in die design is the positioning of the runners and gates. Well-designed gates permit rapid flow into the die cavity, minimizing turbulence and long flow paths for the molten metal.
Aluminum-Manufacturing Methods
Published in Raghu Echempati, Primer on Automotive Lightweighting Technologies, 2021
The advantage of die casting as opposed to other methods of casting is that intricate detail and the best surface finish can be achieved of any of the casting methods. This surface finish and detail is due to the high pressures employed during the solidification process coupled with the smooth die surface. Another advantage is that die casting promotes extremely fast production. Unlike sand or permanent mold casting, die casting allows for thin casting walls as well as have cast-in inserts, such as threaded inserts, heating elements, and high strength-bearing surfaces. Despite the advantages, there are limitations to die casting. The biggest limitation is that the steel dies are not permeable. Vents are required for gases to escape and care must be taken to ensure that the pressurized molten aluminum does not escape through the vents. High melting-point metals cannot be die-cast because the molds cannot withstand the high temperatures. Additionally, the initial cost of getting a die-cast-manufacturing operation set-up is high due to the high cost of dies and any automation features. Another disadvantage of die casting is that the final casting will have a very small amount of porosity that prevents any heat treating or welding which causes microcracks inside the part and exfoliation of the surface. Lastly, thermal fatigue is a concern for the molds used in die casting.
A study on the construction of die-casting production prediction model by machine learning with Taguchi methods
Published in Journal of the Chinese Institute of Engineers, 2023
Yung-Tsan Jou, Riana Magdalena Silitonga, Ronald Sukwadi
Die casting is a permanent mold casting process since the process utilizes reusable metallic dies. After the metal raw material melts, it will enter the mold cavity under high pressure. The die casting is more valuable in any intricate shape, such as narrow and complex ones, with minimizing the defective casting. Therefore, this process is better than conventional casting, which involves more defects and consumes more time (Sodhi 2018). We call the finished product a casting. Because the mold used in the casting operation is a steel mold (die), this operation is called die casting. Unlike other permanent molds, die-casting uses high pressure to force the liquid metal into the mold cavity (Adke and Karanjkar 2014).
Manufacturing methods for metallic bipolar plates for polymer electrolyte membrane fuel cell
Published in Materials and Manufacturing Processes, 2019
Oluwaseun Ayotunde Alo, Iyiola Olatunji Otunniyi, HCvZ Pienaar
Generally, die casting has been mostly limited to non-ferrous, high-fluidity metals such as aluminum, magnesium, lead, zinc and tin-based alloys.[119,121–125] Furthermore, studies on the fabrication of BPs using die casting process have focused on aluminum alloys.[21,116,120] The challenge in die casting ferrous metals such as SSs is their higher melting points compared to non-ferrous metals, which due to the low melting points of most die casting-die alloys (usually tool steel), leads to a poor working condition for the die and injection system.
ELF-MF occupational exposure in die-casting and electroplating workers in Korea
Published in International Journal of Occupational Safety and Ergonomics, 2020
Rajitha Kawshalya Mailan Arachchige Don, Joon-Sig Jung, Yun-Jin Lee, Seung-Cheol Hong
Electroplating uses electric current to reduce dissolved metal cations to form a thin coherent metal coating on an electrode. The electroplating plant selected in this study processes vehicle assembly parts, such as car door handles, buffers, rims and hoods. At the die-casting plant, a metal casting process is used that drives liquid metal under high pressure into a mold cavity. Die castings are mostly made from non-ferrous metals such as zinc, copper, aluminum, lead or magnesium. The die-casting plant in this study was a hot chamber plant.