| 초록 |
The joint, formed by the laser metal deposition of V, followed by 17-4PH stainless steel Ti-6Al-4V has been investigated. The microstructure and mechanical properties of the joint was compared to similar reported Ti-6Al-4V//V//17-4PH stainless steel joint, processed with alternate joining technique such as welding. A defect-free joint interface with an unprecedented high tensile strength of 574 MPa was achieved after the laser metal deposition process. This ultimate tensile strength was greater than that of the pure V interlayer and most similar joints, formed by welding. The narrow fusion zone (FZ), negligible HAZ and the presence of the compositional graded V-Fe with low V concentration in the V//17-4PH FZ, coupled with the smaller grain size influenced the higher bonding strength achieved by most additive manufactured Ti-6Al-4V/V/stainless steel joint as compared to welding. In comparing the present joint with similar additive manufactured joint from previous work in which the V interlayer was diffusion bonded to the Ti-6Al-4V, the presence of the functionally graded Ti-V interlayer exhibited a higher strength which formed strong bonds and interlocks with the 17-4PH stainless steel and contributed to the very high tensile strength. |
