J. Jpn. Inst. Light Met. 65(6): (2015)

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1 ** Journal of The Japan Institute of Light Metals, Vol. 65, No. 6 (2015), The Japan Institute of Light Metals Investigation of heat flow behavior on die-casting core pin with direct measurement of die surface temperature and heat flux Suguru TAKEDA* and Shin ORII* Thermal behavior between casting and core pin/die in high pressure aluminum die-casting was investigated with direct temperature measurement by calculating surface temperature and heat flux. It is proved that there are three heat transfer stages from casting to core pin and that furthermore three types of heat flux curves are there depending on casting volume and cooling conditions. Under sufficient cooling conditions with higher heat flux, the surface temperature of core-pin would not exceed solidus temperature and chilled structure appears on the surface of the casting. On the other hand, insufficient cooling conditions, no chilled structure could be observed but spheroidization of eutectic silicon particles with soldering defects on the surface could be expected. (Received October 28, 2014 Accepted February 28, 2015) Keywords: heat transfer, heat flux, die surface temperature, aluminum high pressure die-casting, core pin CAE 8 12 Fig. 1 2 Fig. 1 Typical die-casting shapes: plate and cylinder. * Technical Center, Ahresty Corporation (1 2 Nakahara, Mitsuya-cho, Toyohashi-shi, Aichi ) [email protected]

and Shin ORII* Thermal behavior between casting and core pin/die in high pressure aluminum die-casting was investigated with direct temperature measurement by calculating surface temperature and heat

2 J. JILM ϕ10mm ϕ30mm ϕ50mm 2 Fig. 2 Fig. 3 ϕ7mm 7 Table 1 Table 2 ADC12Al 11%Si Cu Mg Fig. 4a 2 X 1, X 2 θ 1, θ 2 13 Fig. 4b Table 1 Casting conditions. Parameters Value Metal pressure (MPa) 57.8 Shot weight (kg) 0.8 Tip diameter ϕ80 Filling percentage at second phase (%) 70 Curing time (s) 7 Plunger speed (m/s) 2.0 Gate velocity (m/s) 30.0 Holding temperature (K) Die temperature (K) Alloy ADC12(JIS) Table 2 Experimental conditions. Experimental number Casting outer diameter (mm) Core pin diameter outer (inner) (mm) Water line pressure (MPa) Fig. 2 Schematic illustration of casting (7) Fig. 3 Schematic illustration of sensing point in detail. Fig. 4 Detecting principal of surface temperature and heat flux.

0 Holding temperature (K) 96315 Die temperature (K) 39315 Alloy ADC12(JIS) Table 2 Experimental conditions.

3 Fig mm K 5 1 ms θϕ Fig. 3 1a1b 2 2a 2b SKD W/m K Fig. 5 Measured surface temperatures and heat fluxes of die and core pin at cooling line pressure 0.1 MPa. 中子ピン表面温度 : Θ= θ ( ( ln( r/ r )/ln( r / r )) ( θ θ ) (1a) 中子ピン熱流束 :φ =2 πλ ( θ θ )/ l n( r / r ) (1b) 金型の表面温度 : Θ= θ (( θ θ ) x )/( x x ) (2a) 金型の熱流束 :φ = λ ( θ θ )/( x x (2b) ) Θ θ 2 θ 1 x 2, r 2 x 1, r 1 λ ϕ 3. Fig. 5Fig K kw/m Fig Fig. 6 Measured surface temperatures and heat fluxes of die and core pin at cooling line pressure 1.9 MPa. 790 K Fig Fig. 7

中子ピン表面温度 : Θ= θ ( ( ln( r/ r )/ln( r / r )) ( θ θ ) (1a) 2 2 1 2 2 1 中子ピン熱流束 :φ =2 πλ ( θ θ )/ l n( r / r ) (1b) 1 2 1 2 金型の表面温度 : Θ= θ (( θ θ ) x

4 J. JILM K Fig ϕ MPa ϕ MPa Fig. 9 ϕ50 Fig. 9 Si 1 mm Si Fig Fig I II I III 3 A B C Fig. 7 Measured surface temperatures and heat fluxes of die and core pin at cooling line pressure 0.1 MPa. Fig. 9 Optical microstructures in typical conditions. Fig. 8 Measured surface temperatures and heat fluxes of die and core pin at cooling line pressure 1.9 MPa. Fig. 10 Heat flux curves in various conditions.

7 Measured surface temperatures and heat fluxes of die and core pin at cooling line pressure 0.1 MPa. Fig.

5 Fig. 11 Surface temperature in various conditions. Fig I Fig. 9 Fig. 9 Si Si Fig. 9 I Si Si 3 Si I II III Si 1) 1990 JD ) ) ) ) ) ) Y. Hatamura, K. Shirahige, Y. Mochiku and S. Takeda: Trans. 15th International Die Casting Congress, (1989), paper No. G-T89-023, ) ) ) M. Jabbari, A. F. Ilkhchy and P. Davami: Journal of Materials Science and Engineering with Advanced Technology, 4 (2011), ) Z. Sun, H. Hu and X. Niu: Metall. Mater. Trans., B, 43 (2012), ) )

15th International Die Casting Congress, (1989), paper No. G-T89-023, 1 7. 8) 62 1990 827 832. 9) 67 1995 689 695. 10) M. Jabbari, A. F. Ilkhchy and P.

Fig. 1 Sampling positions from the ingot. Table 2 Chemical compositions of base metal (%) Fig. 2 (unit: mm) Shape and size of fatigue test specimen. T

Fig. 1 Sampling positions from the ingot. Table 2 Chemical compositions of base metal (%) Fig. 2 (unit: mm) Shape and size of fatigue test specimen. T Friction welding of ADC 12 aluminum alloy diecastings Kazuyoshi KATO* and Hiroshi TOKISUE* Both squeeze and gravity castings of ADC 12 aluminum alloy were friction-welded, using a brake type welding machine.