In this study, Mg/Al bimetallic composite tubes (BCTs) were successfully fabricated using the hot power spinning (HPS) process, and the width of the interface diffusion zone was effectively controlled by adjusting the annealing time and temperature. The shear fracture mechanism and microstructure evolution of the Mg/Al BCTs were investigated using various microscopic characterization techniques and mechanical tests. The results showed that as the diffusion zone length increased from 6.27 µm to 18 µm, the shear strength improved from 14.21 MPa to 26.89 MPa. However, when the diffusion band was further expanded, a brittle intermetallic compound (IMC) layer, composed of Mg₁₇Al₁₂ and Al₃Mg₂, formed, which reduced the interfacial bonding strength. When the annealing temperature was raised to 400 ℃, a Kirkendall void layer developed at the interface, decreasing the shear strength to 4.32 MPa. On the Al side, static recrystallization significantly reduced the grain size, and a more pronounced Goss texture appeared. On the Mg side, a large number of abnormally grown grains were continuously broken down into finer grains under the influence of annealing twins, and the c-axis of the grains showed significant alignment in the rolling direction (RD). When the diffusion layer formed Mg₁₇Al₁₂ and Al₃Mg₂, the interface exhibited a distinct equiaxed crystal morphology, and the grains grew radially along with the expansion of the IMCs. These findings enhance the understanding of the manufacturing process of Mg/Al BCTs and provide valuable insights for regulating the interface structure and bonding strength of Mg/Al BCTs.

The tube spinning process has attracted much attention because of its simple tooling and good surface finish. This review presents a comprehensive survey of the tube spinning process with a focus on different tube blank materials and spinning methods. The review aims to elaborate the research status of tube spinning process from the aspects of tube material, spinning method and processing performance, and act as a guide for researchers working on tube production and spinning process. In addition, the spinning process will produce large plastic deformation, which will lead to the change of the microstructure of the tube and change its mechanical properties. Therefore, the relationship between the mechanical properties of the tube blank and the spinning parameters is comprehensively expounded from the aspects of yield strength, elongation and material microstructure, and the element diffusion and interface bonding mechanism in the spinning process of the composite tubes are emphatically introduced. In particular, the latest development and trend of composite materials and composite spinning process in tube blank spinning process are discussed. The challenges and prospects of the development of the tube spinning process are put forward, and the direction for future research is pointed out.

Uncontrolled residual stresses have significant effects on the service time and defects of the spun parts. Nowadays, X-Ray Diffraction (XRD) method has been widely used in the residual stress measurement of industry products with different forming processes. The calculated residual stress is usually obtained from the data fitting slope of strain and angle with Ordinary Least Squares (OLS) method. But this fitting method is not always suitable for the big fluctuant data. In this paper, the Weighted Least Square (WLS) method is used for the data fitting and compared with the OLS method. The nickel-based superalloy GH3030 and iron-based superalloy GH1140 are applied in the multi-pass cold spinning experiments. The residual stress distributions of normal, potential crack and wrinkle workpieces are discussed with the grain structure. The results show that WLS method has better goodness of fit compared with OLS method. The residual stress distributions have special relationship with potential crack, wrinkle workpiece and grain structure.