دورات هندسية

 

 

مساعده

النتائج 1 إلى 2 من 2
  1. [1]
    الصورة الرمزية dot4
    dot4
    dot4 غير متواجد حالياً

    عضو فعال

    تاريخ التسجيل: Apr 2009
    المشاركات: 51
    Thumbs Up
    Received: 0
    Given: 2

    مساعده

    انا سنه اولى بالصناعيه بدي تقرير عن صب المعادن

    من مواضيع dot4 :


    0 Not allowed!



  2. [2]
    محمد فوزى
    محمد فوزى غير متواجد حالياً
    عضو شرف
    الصورة الرمزية محمد فوزى


    تاريخ التسجيل: Jun 2005
    المشاركات: 243

    وسام الشكر

     وسام كبار الشخصيات

    Thumbs Up
    Received: 0
    Given: 0
    Casting
    From Wikipedia, the free encyclopedia
    Jump to: navigation, search
    Engineering portal

    Casting iron in a sand mold
    Casting may be used to create artistic sculpturesThis article is about the manufacturing process. For other uses, see Casting (disambiguation).
    For molding plastics, see Molding (process).
    Casting is a manufacturing process by which a liquid material is usually poured into a mold, which contains a hollow cavity of the desired shape, and then allowed to solidify. The solidified part is also known as a casting, which is ejected or broken out of the mold to complete the process. Casting materials are usually metals or various cold setting materials that cure after mixing two or more components together; examples are epoxy, concrete, plaster and clay. Casting is most often used for making complex shapes that would be otherwise difficult or uneconomical to make by other methods.[1]

    Casting is a 6000 year old process.[2] The oldest surviving casting is a copper frog from 3200 BC.[2]

    *******s [hide]
    1 Types
    1.1 Metal
    1.2 Plaster, concrete, or plastic resin
    2 References
    2.1 Notes
    2.2 Bibliography
    3 External links



    [edit] Types

    [edit] Metal
    Main article: Casting (metalworking)
    Metal casting is the most common casting process.


    [edit] Plaster, concrete, or plastic resin
    Main article: Resin casting
    Plaster itself may be cast, as can other chemical setting materials such as concrete or plastic resin - either using single-use waste molds as noted above or multiple-use piece molds, or molds made of small ridged pieces or of flexible material such as latex rubber (which is in turn supported by an exterior mold). When casting plaster or concrete, the finished product is, unlike marble, relatively unattractive, lacking in transparency, and so it is usually painted, often in ways that give the appearance of metal or stone. Alternatively, the first layers cast may contain colored sand so as to give an appearance of stone. By casting concrete, rather than plaster, it is possible to create sculptures, fountains, or seating for outdoor use. A simulation of high-quality marble may be made using certain chemically-set plastic resins (for example epoxy or polyester) with powdered stone added for coloration, often with multiple colors worked in. The latter is a common means of making attractive washstands, washstand tops and shower stalls, with the skilled working of multiple colors resulting in simulated staining patterns as is often found in natural marble or travertine.

    0 Not allowed!



  
الكلمات الدلالية لهذا الموضوع

عرض سحابة الكلمة الدلالية

RSS RSS 2.0 XML MAP HTML