With the upgrade of additive manufacturing (AM) equipment, pure copper and various Cu-based alloys with almost full density have been successfully produced, maintaining their excellent thermal and electrical conductivity and good mechanical properties at high temperatures as well. In this paper, a model with a series of inclined surface structures was designed and fabricated to investigate the structural design on the formability of CuCrZr alloy produced by laser powder bed fusion (LPBF). The typical structure dimensions of the as-built samples were measured and compared with their corresponding dimensions and the inclined angle (α) and the relative angle (γ) between the inclined surface and recoating directions. The results demonstrate that the inclined structures with α < 50° were fabricated either with varying buckling deformation and powder adhesion or in failure for severe distortion. The differences (L_d) between the typical structure dimensions and their models increase with the decreasing of α. It has been observed that L_d reaches 1 mm when α is 20° and drastically reduces to around 200 μm when α is above 50°. When α < 50°, L_d is generally increasing with a rising γ value from 0° to 180°, significantly affecting the dimensional accuracy.

The continuously annealed low-carbon-steel strips from industrial production showed an average aging index of about 30 N/mm². This increase in yield strength caused by the continuous-annealing process was strongly dependent on the soaking temperature and the soaking time. Whilst the optimization of the overaging parameters and the use of a higher annealing temperature would reduce the ageing susceptibility of low-carbon-steel strips, it was considered unlikely that its magnitude could be reduced to a comparable level to that of the batch-annealed one. Within the limit of low-carbon-strip specifications, there was very little effect of the C content on the ageing. The aging index of the temper-rolled materials decreased with the increase in the temper-rolling reductions, and a maximum increase in yield strength was achieved at a temper-rolling reduction of about 1%. In this work, the effect of C content, Al content, continuous-annealing cycles, and temper-rolling reduction on the ageing susceptibility of the continuously annealed low-carbon-steel strips was examined. SEM/EBSD technique was developed to characterize the temper-rolling strain bands and to assess the effect of temper-rolling reduction on the yield strength of the low-carbon-steel strips.

Chromium nitride powder is blended with pre-alloyed powder to make an overmatched powder with a high nitrogen concentration in order to manufacture high-nitrogen steel by selective laser melting. By employing a wider range of process parameters, the impact of process parameters on the relative density, nitrogen concentration, microstructure, and mechanical properties of high-nitrogen steel is investigated. In simulated human body fluid conditions, the corrosion resistance of high-nitrogen steel, pure titanium, and 316L was compared and evaluated. The findings demonstrate that the relative density of high-nitrogen steel initially rises and then falls with the increase in energy density, reaching a high value of 98.8% at 148.8 J/mm³. With rising energy density, the nitrogen concentration falls. The microstructure of high-nitrogen steel is mainly composed of columnar and cellular grains. Both grain sizes steadily grow, but their mechanical characteristics initially rise and then fall as the energy density rises from 83.3 to 187.3 J/mm³. With yield strength, tensile strength, and elongation reaching 921.9 MPa, 1205.1 MPa, and 27%, respectively, the alloy exhibits outstanding mechanical characteristics when the laser power is 250 W, the scanning speed is 700 mm/s, and the associated energy density is 148.8 J/cm³. The high-nitrogen steel at an energy density of 148.8 J/mm³ has the lowest corrosion rate when compared to pure titanium and 316L steel, which suggests that the HNS alloy will have good corrosion resistance in human body fluid conditions.