TY - JOUR
T1 - Filling system for investment case Ni-base turbine blades
AU - Li, DZ
AU - Campbell, John
AU - Li, Y
PY - 2004/5/30
Y1 - 2004/5/30
N2 - In investment foundries, it is usual to pay relatively little attention to the design of the filling system of a casting. Vacuum-cast turbine blades represent a typical case, where the mould filling process is poorly controlled, the mould cavities themselves often being top-filled. The consequential surface turbulence causes the entrapment of oxide film on the liquid surface, despite the use of vacuum melting and pouring. In this work, bottom filling principles were used to minimize turbulence. X-ray radiographic video was used to observe and compare the filling of both bottom- and top-filled moulds. Ni-based alloy investment-cast blades melted and cast in vacuum clearly validated the bottom filling design. Compared to conventional top filling in vacuum, dye penetrant indications were reduced by approximately a factor of 10, and hot cracking appeared to be eliminated. (C) 2004 Elsevier B.V. All rights reserved.
AB - In investment foundries, it is usual to pay relatively little attention to the design of the filling system of a casting. Vacuum-cast turbine blades represent a typical case, where the mould filling process is poorly controlled, the mould cavities themselves often being top-filled. The consequential surface turbulence causes the entrapment of oxide film on the liquid surface, despite the use of vacuum melting and pouring. In this work, bottom filling principles were used to minimize turbulence. X-ray radiographic video was used to observe and compare the filling of both bottom- and top-filled moulds. Ni-based alloy investment-cast blades melted and cast in vacuum clearly validated the bottom filling design. Compared to conventional top filling in vacuum, dye penetrant indications were reduced by approximately a factor of 10, and hot cracking appeared to be eliminated. (C) 2004 Elsevier B.V. All rights reserved.
KW - casting Ni-base
KW - turbine blade
KW - defects
KW - investment
UR - http://www.scopus.com/inward/record.url?scp=2342511419&partnerID=8YFLogxK
U2 - 10.1016/j.jmatprotec.2004.02.032
DO - 10.1016/j.jmatprotec.2004.02.032
M3 - Article
VL - 148
SP - 310
EP - 316
JO - Journal of Materials Processing Technology
JF - Journal of Materials Processing Technology
ER -