Research on fabrication and microstructure between carbon steel double wire and single wire plasma arc additive manufacturing

Aiming at the low efficiency and high quality of deposited carbon steel component by using conditional single-wire feed and plasma arc additive manufacturing process, a novel process named double-wire feed and plasma arc additive manufacturing process is proposed. Low carbon steel components were successfully manufactured by this process, then the characterization of deposition size, microstructure and mechanical properties of all samples deposited by two processes were compared. The results show that, under the same process conditions, compared with the single-wire feed and plasma arc additive manufacturing process, the deposition rate of the double-wire feed and plasma arc additive manufacturing process improved by 0.97 times. The average grain size of the samples deposited by double-wire feed and plasma arc additive manufacturing process is fined from 18.75 μm to 13.75 μm on an average. The ultimate tensile strength in vertical direction of the deposited samples is increased by 62.64 MPa, and that in horizontal direction is increased by 67.52 MPa. Moreover, the mean Micro Vickers Hardness of the effective deposited layer raised from 158.95 HV to 175.34 HV.