横向交变磁场对铝合金电弧增材成形组织与性能的影响

Effect of Transverse Alternating Magnetic Field on the Microstructure and Properties of Aluminum Alloy Arc Additive Forming

为细化铝合金电弧增材成形组织晶粒、减少组织缺陷、提高熔覆层的力学性能,在电弧增材成形过程中耦合横向交变磁场制备了铝合金熔覆层,并对熔覆层微观组织结构和力学性能进行表征分析,研究了在横向交变磁场中励磁电流变化对熔覆层组织和性能的影响。结果表明:在磁场作用下,凝固组织中粗大柱状晶数量减少,等轴晶数量增多,晶粒尺寸细化。当励磁电流为11 A时,熔覆层截面平均显微硬度为83.9HV,较无磁场时提高近10%。当励磁电流为8 A时,在横、纵两方向上抗拉强度分别为275.7 MPa、254.3 MPa,平均延伸率分别为21.9%、26.2%,综合力学性能均高于未引入磁场。

In order to refine the grain size,reduce the defects and improve the mechanical properties of the deposited layer,the aluminum alloy deposited layer was prepared by coupling the transverse magnetic field during the arc additive forming process.The microstructure and mechanical properties of the deposited layer were characterized and analyzed,and the influence of the excitation current change on the microstructure and properties of the deposited layer in the transverse alternating magnetic field was studied.The results show that with the action of magnetic field,the number of columnar crystals and equiaxed crystals are decreased and increased respectively,and the grain size was refined.When the excitation current was 11 A,the microhardness of the deposited layer was 83.9HV on average,which was nearly 10%higher than that without magnetic field.When the excitation current was 8 A,the tensile strengths in transverse and longitudinal directions were 275.7 MPa and 254.3 MPa respectively,and the elongations were 21.9%and 26.2%on average,respectively.The comprehensive mechanical properties were higher than that without magnetic field.