This study investigated the effects of four heat treatment processes on the microstructure, damping capacity, and mechanical properties of Mn-Cu alloys. The results indicated that the alloy did not undergo spinodal decomposition and twinning after solution treatment. After solution and aging treatment, the alloy underwent spinodal decomposition and formed Mn-rich regions, increasing the martensitic transformation temperature (M_s), promoting martensitic transformation, forming twin boundaries, and enhancing damping capacity and mechanical properties. The cryogenic treatment and furnace cooling process facilitated the process, promoted the formation of twin boundaries, and improved damping capacity, and the degree of promotion by furnace cooling process was more significant. In addition, cryogenic treatment promoted grain refinement, increased dislocation density, improved strength, and facilitated the improvement of mechanical properties. This provided a reference for preparing high-damping Mn-Cu alloys with good comprehensive performance.

This study systematically investigates the influence of different heat treatment processes on the microstructural evolution and mechanical properties of Cu-15Ni-3Al alloys, with particular emphasis on the synergistic strengthening mechanisms of spinodal decomposition and precipitation hardening. Two distinct aging routes—solution aging and direct aging—were designed to facilitate a comparative assessment of microstructural characteristics and their correlation with mechanical performance. Comprehensive characterization was conducted using scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and room-temperature tensile testing to elucidate the structure–property relationships. The results reveal that direct aging promotes the formation of fine, coherent L1₂-type Ni₃Al precipitates and the evolution of Ni-enriched regions initially generated through spinodal decomposition into stable Ni₃Al precipitates. These microstructural features act as effective barriers to dislocation motion, thereby significantly enhancing both strength and ductility. The findings provide valuable insights into optimizing heat treatment strategies to improve the performance of Cu-Ni-Al alloys.

It is still challenge to fabricate copper alloys due to excellent thermal properties and high reflective to laser beams during Laser powder bed fusion (LPBF) process. As such, the short-wavelength green laser beam has been employed in present work to fabricate copper-chromium-zirconium (CuCrZr) alloys in present work. To enhance performance, post-heat-treatment was employed on the alloys. The mechanical properties in present work are superior to most of LPBF-built CuCrZr alloys using conventional infrared laser. So far, most of studies about additive manufactured (AM-ed) CuCrZr alloys only focus properties of alloys perpendicular to build directions. Hence, the mechanical behaviors (tensile properties and Vick Hardness tests) and physical properties (electrical and thermal conductivities) of LPBF-built alloys along different build orientations were investigated. In order to reveal the microstructures of the alloys, the characterizations of scanning electron microscope (SEM), transmission electron microscope (TEM) and electron backscatter diffraction (EBSD) were performed, including texture, misorientation angle, Schmid factor. The slender columnar grains were observed. Nevertheless, heat-treated samples along transverse directions own better mechanical properties (yield strength (YS): 505 MPa, ultimate tensile strength(UTS): 585 MPa, Elongation (EL): 14.4%) and better thermal properties (307 W/mK). While the heat-treated samples along build directions own lower strength (YS: 472 MPa, UTS: 495 MPa) with better ductility (EL: 17.8%) and poor thermal conductivity (255 W/mK). The mechanical and thermal anisotropy attributes the stronger {110} grain orientation and lower fraction of LAGBs along build directions due to the columnar structure with fine equiaxed grains.