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    День рождения:
    10 фев 1995 (Возраст: 29)
    Сайт:
    http://www.wabonmetal.com/our-services/investment-casting/
    Investment casting has been used to manufacture weapons, jewellery

    and

    investment casting
    during the ancient civilization. Today, its

    applications include jewellery/art castings, turbine blades and many

    more industrial/scientific components. The present paper reviews

    various investigations made by researchers in different stages of

    investment casting and highlights their importance. The paper initially

    highlights the investigations made on pattern wax properties, effects

    of blending, additives and fillers. Different ways through which

    pattern properties (like surface finish, dimensional accuracy, etc.)

    could be enhanced by properly controlling the injection processing

    parameters are thoroughly discussed. The paper also looks into the

    investigations made to enhance the strength, surface finish, etc. of

    ceramic shell for ferrous alloys/non-ferrous alloys as well as

    superalloys in investment casting. Investigations made on incorporation

    of nylon fibers and polymer additions confirm that a ceramic shell

    reinforced with nylon fibers attains additional permeability compared

    to the one with polymer additions.

    Different investigations carried out on autoclave dewaxing and

    microwave dewaxing conclude that the wax properties are less altered

    with microwave dewaxing when compared to an autoclave dewaxing. Some

    recent investigations carried out on pouring and post-treatment

    operations are also discussed in the paper. The advent and emergence of

    rapid prototyping in shell mold casting are broadly

    exposed in the subsequent sections of the paper. Various aspects of

    rapid prototyping like rapid investment casting, rapid freeze

    prototyping, etc., along with their advantages are projected. The

    emerging areas of applications of rapid prototyping like dentistry,

    etc., are duly discussed.


    The casting of titanium based alloys presents considerable problems,

    including the extensive interactions that occur between the metal and

    refractory. In this work, CaO stabilised zirconia was used as a primary

    coat material on the investment casting mould. The reaction between the

    zirconia face-coat and a Ti-46Al-8Nb-1B alloy was evaluated at three

    mould pre-heating temperatures: 500°C, 1000°C and 1200 °C. The

    effect of casting dimensions on interaction was also included in this

    work and the computer simulation of metal cooling profiles was carried

    out to assist the analysis. Higher mould pre-heat temperature and

    larger casting dimensions enhanced the interaction between the shell

    and the TiAl alloy associated with longer metal solidification time.

    During the high temperature casting process, not only were O and Zr

    observed penetrating into the metal from the decomposition of the

    face-coat materials, but also Si which had penetrated from the backup

    coat was found to have interacted with the metal.


    Investment casting is competitive with all other casting processes

    where the size of the product is within a mutually castable range.

    Though investment casting is used to produce metal parts of any

    intricate shapes with excellent surface finish, it suffers from long

    lead time and high tooling costs, which makes it uneconomical for the

    production of either single casting, or small and medium production

    units. These problems could be overcome by the applications of rapid

    prototyping and rapid tooling technologies for low-volume investment

    casting production runs. The present article analyzes different

    classifications of rapid prototyping techniques and it reviews various

    investigations made on the usability of rapid prototyping- and rapid

    tooling-integrated investment casting process, with their advantages

    and limitations. The emerging areas of applications of rapid

    prototyping like dentistry, jewelry, surgical implants, turbine blades,

    etc., are accordingly discussed. Further, an elaborate discussion is

    made on the application of newer technologies for directly developing

    ceramic shells. This article also emphasizes on various future scopes

    possible in rapid prototyping-integrated investment casting process.




    Investment casting
    process is known to its capability of

    producing clear net shape, high-dimensional accuracy and intricate

    design. Consistent research effort has been made by various researchers

    with an objective to explore the world of investment casting.

    Literature review revealed the effect of processing parameters on

    output parameters of cast specimen. This article highlights the

    advancements made and proposed at each step of investment casting and

    its hybridization with other process. Besides, investment casting has

    always been known to manufacture parts such as weapons, jewellery item,

    idols and statues of god and goddess since 3000 BC; this article

    reviews the present applications and trends in combination of rapid

    prototyping technique as integrated investment casting to serve in

    medical science. Advancements in shell moulding with incorporation of

    fibre and polymer, development of alternative feedstock filament to

    fused deposition modelling are duly discussed. The aim of this review

    article is to present state of art review of investment casting since

    3200 BC. This article is organized as follows: in section

    ‘Introduction’, introduction to investment casting steps is given

    along with researches undertaken at each step; in section ‘Rapid

    prototyping technique’, background is given on the concept of rapid

    prototyping technique by examining the various approaches taken in the

    literature for defining rapid prototyping technique; section

    ‘Biomedical applications of RPT’ presents the medicine or biomedical

    applications of investment casting and rapid prototyping technique;

    section ‘Future trends’ provides some perspectives on future research

    and section ‘Conclusion’ closes the article by offering conclusions.


    In order to improve the properties of silicon sol shell for

    shell

    mold casting
    process, natural plant fibers combined with aluminum

    silicate fibers at natural-to-aluminum silicate fibers mass ratio of

    1:1 were mixed into the slurries preparing for fiber-reinforced shell.

    The flexural strength of specimens of green shells, fired shells at

    different temperatures and the self-loaded deformation of the latter at

    elevated temperature were investigated. The fracture surface of shell

    specimens was observed by SEM. The results show that the green strength

    of shell specimens increases firstly and then decreases with variation

    of content of fiber from 0.2% to 1.0%. However, the self-loaded

    deformation at elevated temperature firstly decreases and then

    increases. The green strength of shell specimens reinforced with 0.6%

    fibers reaches the maximum of 2.94 MPa. The bending strength of shell

    specimens reinforced with 0.6% fibers fired at 900℃ reaches 4.04 MPa,

    approaching that of the non-reinforced shell specimens. It is found by

    SEM that the failure of the fiber-reinforced shell specimens at the

    applied load is resulted in breakdown of silicon sol films and

    pulling-out, fracturing and debonding of fibers in the shell.

    The development of manufacturing processes for high-performance

    investment casting components in turbomachinery is an iterative

    process, which takes a lot of development time for engineers and

    foundry occupation. The reduction of these expensive preliminary tests

    is possible by combining probabilistic methods with modern simulation

    tools for the numerical description of the

    what is investment casting and

    solidification processes. Starting from the deterministic simulation of

    the casting process, the casting and solidification parameters

    including their production tolerances are taken into account in the

    probabilistic simulation.