In Situ Investigation of Si-Poisoning Effect in Al–Cu–Si Alloys Inoculated by Al–5Ti–1B

In situ synchrotron X-radiography was carried out on Al–13Cu and Al–13Cu–7Si alloys with without addition of Al–5Ti–1B master alloy. The effects Si content grain growth the solute-suppressed nucleation zone (SSNZ) were quantitatively studied. average size can be refined to 164 ?m alloy inoculated by Al–5Ti–1B. After 7% content, a large number TiB2 sites in melt lost inoculating ability due “Si poisoning.” radius dendrite tip curvature is more than two times as that Al–13Cu–7Si. sharper able disperse solute effectively thus grains grow rapidly. This causes arm rate about 2.6 no addition. addition, enrichment SSNZ faster, area change slower Thus cannot activated Si. study will shed light understanding poisoning casting Al–Cu–Si alloys.