Wax pattern module for the directional vane was modified to balance the heat dissipation inner and outer sides of the vane

which can improve the inclined grain defect in the directional vane.Insulation device of ALD directional furnace was modified including decreasing the inner diameter and thickness of the insulation device.Through improving the insulation device

the grain in the directional vane is refined

and the temperature gradient of directional furnace is increased from 40.5 ℃/cm to 49.7 ℃/cm

so the grain structure and temperature gradient of directional furnace are optimized.