KimWonGun
Mechanical
- Oct 11, 2010
- 78
I am experimenting with thermal barrier ceramic coatings and observed that a particular composition consistently adheres to a steel substrate but inconsistently adheres to an aluminum substrate (1 of 3 to 1 of 4). While it appears clear that the difference in the thermal expansion rate between the TBC and aluminum is sufficient to lead to spalling compared to the same TBC and steel, why is the result inconsistent with the aluminum substrate? After several test batches, the coating never fails with steel. I am completely baffled. What am I overlooking?