A Study on the Castability (4th Report). On the Effects of Titanium for Castability in Al-alloys

In former reports, it was stated that the addition of titanium to Al-alloys decreased their solidifying shrinkages and its effects were examined quanitatively, these effects of titanium were very remarkable but in utilization of titanium for Al-alloys, these effects on solidifying shrinkages were not yet positively utilized. In this report, the effects of titanium on castability were studied in co-existence of other prominent elements, such as Si and Cu, using the author’s instrument. The results obtained were as follows: 1. Al-Ti system. The results of this system resemble to the one reported previously in solidifying shrinkage and at 0.4%Ti, the runnability was improved greatly. 2. Al-Si-Ti system. In this system, the addition of titanium was fixed at 0.4% and Si content was changed. An addition of 0.5% Si showed the smallest runnability but the runnability was improved with increasing Si. 3. Al-Cu-Ti system. An addition of 0.5% Cu gave the best runnability in this system but addition of more Cu was not effective in improving the castability even in co-existence with titanium.