Research Article
Effect of Solidification Rate and Rare Earth Metal Addition on the Microstructural Characteristics and Porosity Formation in A356 Alloy
(a) Modifier additions and corresponding A356 alloy codes, graphite mold castings |
| Alloy | Mold type | Mold temp. (°C) | Alloy code | Modifier addition (wt.%) | Aimed | Actual | Sr | La | Ce | Sr | La | Ce |
| A356 | Graphite | 600 | TB | 0 | 0 | 0 | 0 | 0 | 0 | T10 | 0 | 0.2 | 0 | 0 | 0.165 | 0 | T1 | 0 | 0.5 | 0 | 0 | 0.356 | 0 | T2 | 0 | 1 | 0 | 0 | 0.685 | 0 | T3 | 0 | 1.5 | 0 | 0 | 1.025 | 0 | T11 | 0 | 0 | 0.2 | 0 | 0.002 | 0.082 | T4 | 0 | 0 | 0.5 | 0 | 0.006 | 0.185 | T5 | 0 | 0 | 1 | 0 | 0.006 | 0.317 | T6 | 0 | 0 | 1.5 | 0 | 0.009 | 1.088 | T7 | 0 | 0.5 | 0.5 | 0 | 0.442 | 0.282 | T8 | 0 | 1 | 1 | 0 | 0.781 | 0.377 | T9 | 0 | 1.5 | 1.5 | 0 | 1.073 | 0.531 | T10S | 0.01 | 0.2 | 0 | 0.0079 | 0.165 | 0 | T1S | 0.01 | 0.5 | 0 | 0.0109 | 0.356 | 0 | T2S | 0.01 | 1 | 0 | 0.0077 | 0.685 | 0 | T3S | 0.01 | 1.5 | 0 | 0.0077 | 1.025 | 0 | T11S | 0.01 | 0 | 0.2 | 0.0073 | 0.002 | 0.182 | T4S | 0.01 | 0 | 0.5 | 0.0078 | 0.006 | 0.358 | T5S | 0.01 | 0 | 1 | 0.0081 | 0.006 | 0.817 | T6S | 0.01 | 0 | 1.5 | 0.0081 | 0.009 | 1.288 | T7S | 0.01 | 0.5 | 0.5 | 0.0083 | 0.442 | 0.382 | T8S | 0.01 | 1 | 1 | 0.0083 | 0.781 | 0.877 | T9S | 0.01 | 1.5 | 1.5 | 0.0089 | 1.073 | 1.231 |
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(b) Actual Sr concentrations obtained for the step-like and variable angle mold castings of A356 alloy |
| Mold | Alloy code | Sr (ppm) |
| Step-like mold | S12 | 83 | S22 | 95 | S32 | 84 | S42 | 105 | S52 | 108 | S14 | 79 | S24 | 73 | S34 | 77 | S44 | 88 | S54 | 89 |
| Variable angle mold | DBLS | 127 | D10LS | 79 | D1LS | 109 | D2LS | 74 | D3LS | 74 | D11LS | 73 | D4LS | 70 | D5LS | 71 | D6LS | 77 | D7LS | 75 | D8LS | 78 | D9LS | 70 |
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Aimed amount was 100 ppm ± 20 ppm.
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