Research Article
A Review Study on the Main Sources of Porosity in Al-Si Cast Alloys
Figure 9
Porosity formation in Sr-modified A356 alloy: (a) general distribution of porosity (0.25 ml/100 g Al), (b, c) H2 = ∼0.4 ml/100 g Al, (d) optical micrograph shows presence of SrO particles at the bottom of the pore, (e) backscattered electron image of SrO particles viewed in a gas pore-bright spots (Sr atomic number is 38 whereas Al atomic number is 13), (f) O2-X-ray spectrum obtained from the particles in (e). Average dendrite arm spacing is about 25 μm.
| (a) |
| (b) |
| (c) |
| (d) |
| (e) |
| (f) |