by clicking the arrows at the side of the page, or by using the toolbar.
by clicking anywhere on the page.
by dragging the page around when zoomed in.
by clicking anywhere on the page when zoomed in.
web sites or send emails by clicking on hyperlinks.
Email this page to a friend
Search this issue
Index - jump to page or section
Archive - view past issues
button in toolbar for more information.
Metal Casting Technologies : March 2011
Introduction ost of the castings are produced using sand mould, where sand is mixed with a binder and the bonded sand is compacted around a pattern to form a mould cavity. The common binders are clay-water, sodium silicate, various types of resins, molasses etc. Sand-clay- water system is cheap, but can cause moisture related defects in castings. The cost of other binders is relatively high and varies over a wide range. Some of the binders, particularly the resins, pollute the moulding / core making shop and casting area. Therefore attempts have been made to produce castings from a mould made with loose unbounded sand. There are mainly two moulding processes that use loose unbounded sand: Lost Foam Casting (LFC)[1-4] and Vacuum Moulding processes. In LFC, an expanded polystyrene pattern is coated with a thin layer of refractory and moulded in loose unbounded sand in a mould box. Liquid metal is poured in the mould during which the pattern burns and the pattern is replaced by liquid metal. In Vacuum moulding process, a thin plastic film forms the mould cavity by application of vacuum in loose unbounded sand. Due to various constraints, these two processes have found very limited adoption in foundries. In the present article, a new casting process is proposed using sheet metal and loose unbounded sand. Steel casting have been attempted to produce by this process in the initial stage of the investigation. Basic concept of the proposed casting process The proposed Sheet Metal Mould Casting (SMMC) process presented in this article is based on the condition similar to LFC process, where loose unbounded sand is used as the mould material that surrounds a sheet metal body having shape and dimensions similar to that of the casting to be produced instead of an Expanded FEATURE STORY Sheet metal mould casting process -- a new approach to produce castings M Dr. P. C. Maity Metal Casting and Materials Engineer E-Mail: email@example.com 22 www.metals.rala.com.au