Structures And Properties Of Square Ingot Of Ti44Al6Nb Alloy Directionally Solidified With Cold Crucible

Entity modeling and mesh dissection was made on30mm×30mm×115mmelectromagnetic cold crucible by use of ANSYS software in this paper, andelectromagnetic field-the flow field coupling simulation was made on melt underdifferent parameters. Flow velocity increased with different parameters rise. Thevelocity turned to biggest in the corner of the melt.Two components of continuous casting and unidirectional solidification sampleswere prepared by using the30mm×30mm×115mm square electromagnetic water-cooledcopper crucible, and the surface quality of the organization and macro were analysed.The height between the first lap of the coil and the up feeding ingot (from up to downdirection) is7to13mm or so. It beats the best effect when the distance between leadingot and the bottom of the crucible is52mm. Increase power or reduce the diameter offeeding ingot can improve the surface quality. The influence on the solidificationinterface by withdrawal rate is the interface changed from flat to concave to concave toemarginated with the withdrawal rate increases. The equiaxial crystal in solidificatio nfrontier liquid blocked the growth of columnar crystal. The equiaxial crystal grain waslarger, and made the length of columnar crystal shorter. Use the same DiTuo repeated todo unidirectional solidification experiment, initial bubble growth phase of theorganization will has transmissibility.The initial coagulation phase was phase when the withdrawal rate of Ti44Al6Nbwas0.5mm/min, it was β phase in other withdrawal rate. The initial phase whencolumnar crystal growed steady was phase under the withdrawal rate0.7mm/min and1mm/min, when it increased to1.3mm/min, β phase will be the primary phase. Belements will not only fine grains but also can influence the initial solidification phase.The substrate ingredient content of two components was even, The precipitatedphase were mainly borides in Ti44Al6Nb0.9B alloy, and their morphology can be strip,block and granular, no matter in or out of the grain boundareis. The precipitated phaseof Ti44Al6Nb alloy were mainly the element niobium separation materials. XRDanalysis was make in Liquid area, columnar area, the isometric crystal and Intermittentcolumnar area after CET changement taking places. The phase of the four areas are all2and γ phase.The tensile strength of Ti44Al6Nb0.9B alloy can be585MPa in the highest;and the tensile strength of Ti44Al6Nb alloy can be355MPa in the highest. Two of the bubbletensile samples are fracture way brittle fracture.