• 제목/요약/키워드: rheology

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내마모계 Al-Si 재료의 레오로지 성형기술 개발 (I);충진거동 및 결함분석 (Development of Rheology Forming Technology of Wear Resistance Al-Si Materials (I);Filling Behavior and Defect Evaluation)

  • 정홍규;강성수;문영훈;강충길
    • 한국주조공학회지
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    • 제20권6호
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    • pp.368-376
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    • 2000

  • Rheology forming technology has been accepted as a new method for fabricating near net shaped products with lightweight aluminum alloys. The rheology forming process consists of reheating process of billet, billet handling, filling into the die cavity and solidification of rheology formed part. The rheology forming experiments are performed with two different die temperatures ($T_d$ = $200^{\circ}C$, $300^{\circ}C$) and orifice gate type. The filling behavior and various defects of Al-Si materials with wear resistance (A357, A390 and ALTHIX 86S) fabricated in rheology forming process are evaluated in terms of alloying elements and surface non-uniformity. Finally, the methods to obtain the rheology formed products with high quality are described by solutions for avoiding the surface and internal defects.

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A review on viscocapillary models of pre-metered coating flows

  • Youn, Suk-Il;Kim, Su-Yeon;Shin, Dong-Myeong;Lee, Joo-Sung;Jung, Hyun-Wook;Hyun, Jae-Chun
    • Korea-Australia Rheology Journal
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    • 제18권4호
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    • pp.209-215
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    • 2006

  • Recent research results on viscocapillary models of various pre-metered coating flows such as curtain, slide, and slot coatings have been reviewed in this paper. Such one-dimensional models have been simplified from two-dimensional Navier-Stokes equations for viscous coating flows with free surfaces, using integral momentum balances and lubrication approximation. It has been found that these viscocapillary models is capable of predicting flow dynamics in various coating systems, providing the good agreement with results by 2-D models.

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