Effect of La on Mould Wettability and Interfacial Reaction between CMSX-4 Single Crystal Alloy and Ceramic Mould

Abstract

In order to obtain high-quality rare earth containing single crystal blades， the effect of La content on the wettability and interface reaction between CMSX-4 single crystal alloy and ceramic mould was studied by the droplet method.The experimental results show that when the 90×10-6 La is added， the wetting angle between the alloy and the mould decreases slightly， and only Al reacts with SiO2 in the mould and the reaction product is Al2O3. When the La content in the alloy reaches 143×10-6， and the wetting angle between the alloy and the mould decreases significantly， and both La and Al in the alloy react with SiO2 in the mould. Subsequently the La content continue to increase， and the lanthanum aluminate compounds with different La and Al atomic ratios are precipitated at the interface， and the wetting angle changes little. It can be seen that in the present experitment 143×10-6 is the critical content of interfacial reaction of La in CMSX-4 single crystal alloy， and the reaction between La and SiO2 can improve the wettability of the alloy/mould system.

Keywords

• la content； cmsx-4 single crystal alloy； wettability； interfacial reaction