Effect of crystal orientation on microstructure and properties of bulk Fe₂B intermetallic

The effects of Fe₂B-grain orientation on microstructure and properties of bulk Fe₂B intermetallic fabricated by directional and ordinary solidification techniques have been investigated. The results show that unidirectional solidified Fe₂B intermetallic possesses a strong (002) texture in the transverse direction owing to the opposite unidirectional heat-squeeze effect while random Fe₂B grains can be produced under ordinary solidification conditions. The nonoriented Fe₂B intermetallic has the highest linear expansion coefficient of 13.04 × 10^-6 °C^-1 while the microhardness and fracture toughness of transverse Fe₂B intermetallic in the (002) plane are larger than those of Fe₂B with other grain orientations and their values are ∼18.72 GPa and 6.42 MPa·m^1/2, respectively. Liquid zinc corrosion results indicate that unidirectional Fe₂B intermetallic with long axis perpendicular to the direction of liquid zinc corrosion displays the best corrosion resistance to liquid zinc owing to its beneficial barrier effect. The FeB transition phase can naturally form and grow parabolically during liquid zinc corrosion.