Existing Metal Additive Manufacturing processes are fast approaching a matured stage in which a wide range of possibilities are available for the incorporation of the rapid fabrication technology to current industrial...Existing Metal Additive Manufacturing processes are fast approaching a matured stage in which a wide range of possibilities are available for the incorporation of the rapid fabrication technology to current industrial practices. In terms of design conventions, the limitless geometrical freedom allows complex structures including cellular internal grids and lattices to be formed without additional tooling. Repair parts and leveraging components can also be produced on demand when required especially for military assets where large volume of inventory is constantly maintained to ensure operational readiness. In this exemplary work, a feasibility study on using stainless steel material with integrated cellular design to manufacture a guide bracket found on a military vehicle via Selective Laser Melting process was conducted. The results showed appreciably better mechanical performance in using a stainless steel honeycomb as compared to the aluminum alloy used for the original component together with a faster production route through SLM.展开更多
The large size, crack-free Zr_(55)Cu_(30)Al_(10)Ni_(5) bulk metallic glass(BMGs) with the diameter of 54 mm and the height of 15 mm was built by laser solid forming additive manufacturing technology, whose size is lar...The large size, crack-free Zr_(55)Cu_(30)Al_(10)Ni_(5) bulk metallic glass(BMGs) with the diameter of 54 mm and the height of 15 mm was built by laser solid forming additive manufacturing technology, whose size is larger than the critical diameter by casting. The microstructure, tensile and compressive deformation behaviors and fracture morphology of laser solid formed Zr_(55)Cu_(30)Al_(10)Ni_5 BMGs were investigated. It is found that the crystallization mainly occurs in the heat-affected zones of deposition layers, which consist of Al_5Ni_3Zr_2, NiZr_2, ZrCu, CuZr_2 phases. The content of amorphous phase in the deposit is about 63%.Under the compressive loading, the deposit presents no plasticity before fracture occurs. The fracture process is mainly controlled by the shear stress and the compressive shear fracture angles of about39?. The compressive strength reaches 1452 MPa, which is equivalent to that of as-Cast Zr_(55)Cu_(30)Al_(10)Ni_5 BMGs, and there exist vein-like patterns, river-like patterns and smooth regions at the compressive fractography. Under the tensile loading, the deposit presents the brittle fracture pattern without plastic deformation. The fracture process exhibits normal fracture model, and the tensile shear fracture angle of about 90?. The tensile strength is only about 609 MPa, and the tensile fractography mainly consists of micro-scaled cores and vein-like patterns, dimple-like patterns, chocolate-like patterns and smooth regions. The results further verified the feasibility and large potential of laser additive manufacturing on fabrication and industrial application of large-scale BMGs parts.展开更多
The study aims to demonstrate the suitability of the 3DPMD for the production of titanium components with and without reinforcing particles in layer-by-layer design. Various demonstrators are prepared and analyzed. Th...The study aims to demonstrate the suitability of the 3DPMD for the production of titanium components with and without reinforcing particles in layer-by-layer design. Various demonstrators are prepared and analyzed. The microstructure, the porosity and the hardness values of the different structures are compared with each other through metallographic cross-sections. The uniform distribution of the carbides and the interaction with the matrix was analyzed by SEM and EDX.The miller-test method(ASTM G75-07) was used to determine data for the relative abrasivity of the structures. In summary, 3DPMD offers the possibility to produce titanium structures with and without reinforced particles. Using automated routines, it is possible to generate metal structures using welding robots directly from the CAD drawings. Microstructures and properties are directly related to the process and therefore material-process-property relationships are discussed within this work.展开更多
文摘Existing Metal Additive Manufacturing processes are fast approaching a matured stage in which a wide range of possibilities are available for the incorporation of the rapid fabrication technology to current industrial practices. In terms of design conventions, the limitless geometrical freedom allows complex structures including cellular internal grids and lattices to be formed without additional tooling. Repair parts and leveraging components can also be produced on demand when required especially for military assets where large volume of inventory is constantly maintained to ensure operational readiness. In this exemplary work, a feasibility study on using stainless steel material with integrated cellular design to manufacture a guide bracket found on a military vehicle via Selective Laser Melting process was conducted. The results showed appreciably better mechanical performance in using a stainless steel honeycomb as compared to the aluminum alloy used for the original component together with a faster production route through SLM.
基金supported by the National Key Research and Development Plan of China (2016YFB1100100)the National Natural Science Foundation of China (Grant Nos. 51323008, 51501154 and 51565041)
文摘The large size, crack-free Zr_(55)Cu_(30)Al_(10)Ni_(5) bulk metallic glass(BMGs) with the diameter of 54 mm and the height of 15 mm was built by laser solid forming additive manufacturing technology, whose size is larger than the critical diameter by casting. The microstructure, tensile and compressive deformation behaviors and fracture morphology of laser solid formed Zr_(55)Cu_(30)Al_(10)Ni_5 BMGs were investigated. It is found that the crystallization mainly occurs in the heat-affected zones of deposition layers, which consist of Al_5Ni_3Zr_2, NiZr_2, ZrCu, CuZr_2 phases. The content of amorphous phase in the deposit is about 63%.Under the compressive loading, the deposit presents no plasticity before fracture occurs. The fracture process is mainly controlled by the shear stress and the compressive shear fracture angles of about39?. The compressive strength reaches 1452 MPa, which is equivalent to that of as-Cast Zr_(55)Cu_(30)Al_(10)Ni_5 BMGs, and there exist vein-like patterns, river-like patterns and smooth regions at the compressive fractography. Under the tensile loading, the deposit presents the brittle fracture pattern without plastic deformation. The fracture process exhibits normal fracture model, and the tensile shear fracture angle of about 90?. The tensile strength is only about 609 MPa, and the tensile fractography mainly consists of micro-scaled cores and vein-like patterns, dimple-like patterns, chocolate-like patterns and smooth regions. The results further verified the feasibility and large potential of laser additive manufacturing on fabrication and industrial application of large-scale BMGs parts.
文摘The study aims to demonstrate the suitability of the 3DPMD for the production of titanium components with and without reinforcing particles in layer-by-layer design. Various demonstrators are prepared and analyzed. The microstructure, the porosity and the hardness values of the different structures are compared with each other through metallographic cross-sections. The uniform distribution of the carbides and the interaction with the matrix was analyzed by SEM and EDX.The miller-test method(ASTM G75-07) was used to determine data for the relative abrasivity of the structures. In summary, 3DPMD offers the possibility to produce titanium structures with and without reinforced particles. Using automated routines, it is possible to generate metal structures using welding robots directly from the CAD drawings. Microstructures and properties are directly related to the process and therefore material-process-property relationships are discussed within this work.
