Contents lists available at SciVerse ScienceDirect
Journal of Materials Processing Technology journal homepage: www.elsevier.com/locate/jmatprotec
Development of a device for dynamical measurement of the load on casting and the contraction of the casting in a sand mold during cooling
Yuichi Motoyama a,∗ , Hiroki Takahashi a , Yuki Inoue a , Keita Shinji a , Makoto Yoshida b a b
Department of Modern Mechanical Engineering, Graduate School of Waseda University, 3-4-1 Shinjyuku-ku Okubo, Tokyo 169-8555, Japan
Kagami Memorial Laboratory for Materials Science and Technology, Waseda University, 2-8-26, Nishi-Waseda, Shinjyuku-ku, Tokyo 169-0051, Japan
a r t i c l e
i n f o
Received 27 August 2011
Received in revised form 3 February 2012
Accepted 6 February 2012
Available online 13 February 2012
a b s t r a c t
To predict and control the residual stress present in sand castings manufactured via CAE (Computer Aided
Engineering), the mechanical interaction between the casting and the sand mold during cooling must be determined experimentally. A device was developed in this study to determine the load on the casting caused by the resistance of the mold and the contraction of the casting during cooling. Our device consists of two modules that work simultaneously: a module containing a load cell, for measuring the load on the casting during cooling and a module containing an LVDT (Linear Variable Differential Transformer) for measuring the contraction of the casting during cooling. In performance veriﬁcation testing, the device enabled the simultaneous measurement of the load on the sand casting and the contraction of the casting. This measurement was performed dynamically during the cooling process. Additionally, for the case where the contraction of the casting was hindered by the sand mold, the permanent deformation of the casting after shake out (which leads to residual stress in the casting) was successfully measured using our device.
© 2012 Elsevier B.V. All rights reserved.
The presence of residual stress and distortion is a signiﬁcant problem when producing sand castings such as cylinder heads, large presses, and machine tool beds made from cast iron. Therefore, various investigations into this issue have been reported. Jacot et al. (2000) developed mathematical model based on the ﬁniteelement code to predict the microstructure and residual stress in cast iron castings, and the results were veriﬁed against residual stress measurement. Residual stress in the stress lattice, which has been used for evaluating the residual stress in the casting, was both measured and simulated by Gustafsson et al. (2009). Lee and Lee
(2005) simulated the distortion of the marine propeller casting in the sand casting and compared the results to the measurements.
Ahmed and Chandra (1997) studied numerically that how mechanical properties of the sand mold affected the distribution of the residual stress in the copper alloy casting. Daniel et al. (2001) and
Chang and Dantzig (2004) developed the modeling of the sand mold for predicting the residual stress of the sand casting.
According to T.S.32 (1952), three causes of residual stress and distortion in sand castings have been identiﬁed as follows.
∗ Corresponding author. Tel.: +81 3 5286 3329; fax: +81 3 5286 3329.
E-mail address: email@example.com (Y. Motoyama).
0924-0136/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.jmatprotec.2012.02.007 1) Temperature difference within a casting during cooling.
If a temperature difference occurs within a casting during cooling, it causes thermal stress. If thermal stress induces a permanent strain (i.e., a plastic strain, creep strain), the permanent strain leads to residual stress and distortion of the castings after shake out.
2) Sand mold