The microstructure and compressive properties of as-cast NiAl–28Cr–5.8Mo–0.2Hf containing minor Dy

The effect of dysprosium of less than 0.2 wt.% on microstructure and compressive behaviors of NiAl–28Cr–6Mo–0.2Hf eutectic alloy has been investigated by using a combination of OM, TEM, EPMA and compression tests. It is concluded that lamellar refinement instead of eutectic cell refinement can be gained with the small addition of Dy. The Dy addition leads to an enhancement of the compressive strength and ductility of alloy at all testing temperatures. Since the balance of properties is attained at the amount of 0.1 wt.% Dy, the desired Dy content must be more or less 0.1 wt.% for the NiAl–28Cr–6Mo–0.2Hf alloy.