| 304 austenitic stainless steel | Consumable friction stir tool | Equiaxed crystals | The tensile test results show that the yield strength of the original stainless steel bar and the additive deposited part are 380 and 390 MPa, the tensile strength are 710 and 690 MPa, and the elongation are 50 % and 30 %, respectively | Indian Institute of Technology | [78] |
| formed by | |
| dynamic | |
| recrystallization | |
| |
7075 aluminum alloy | Axial addition of rod | | The average hardness of the substrate and the additive raw rod is measured to be 164 HV, and most of the deposited materials exhibit a hardness value higher than 140 HV, comparable to the hardness of the raw rod | Virginia Polytechnic Institute and State University | [79] |
| |
| |
| |
| |
2024 aluminum alloy | Superimposed plate | | The microhardness of the substrate is 130 HV, the minimum hardness of the bottom zone of the additive is 74 HV, and the maximum hardness of the top zone of the additive is 99 HV. The changes of the second phase and the grain cause the microhardness of the additive to be lower than that of the substrate | Nanchang Hangkong University | [80] |
| |
| |
| |
| |
| |
| |
6561 aluminum alloy | Radial layer-by-layer additive | | The tensile strength of the substrate and the additive strip is 465.57 MPa, and the maximum tensile strength of the stable additive zone is 203.67 MPa. The microhardness of the substrate and the additive strip is about 155 and 125 HV, respectively. The microhardness of the stable additive zone gradually decreases from the surface of the topmost additve strip to the interior, but the hardness of the stable additive zone is generally stable at about 60 HV | Northeast Forestry University | [71] |
| |
| |
| |
| |
| |
| |
| |
| |
| |