Copper is widely used in conventional industries owing to its excellent electrical and thermal conductivity. With the growing demand for complex copper components featuring higher manufacturing accuracy， lower cost， and improved material utilization， additive manufacturing （AM） has opened up new opportunities for processing copper and its alloys. This review summarizes the major production routes for copper powders and wires， including electrolytic methods， plasma rotating electrode processing， atomization， wire drawing， and wire fabrication method，and compares their advantages， limitations， and suitable application scenarios. It further highlights recent progress in AM technologies for copper alloys， such as powder bed fusion， directed energy deposition， binder jetting， cold-spray additive manufacturing， and wire-based electron beam additive manufacturing， and systematically discusses their advantages， bottlenecks， and key technical challenges in fabricating copper parts. In addition， the effects of copper’s intrinsic material characteristics—high reflectivity， high thermal conductivity， susceptibility to oxidation， and high thermal expansion coefficient on AM processes are analyzed. Finally， potential mitigation strategies are proposed， including appropriately increasing scan spacing and laser power， switching laser sources， surface modifications， and post-processing treatments.

The development and manufacturing capability of aeroengines embodies the country's comprehensive national strength and the level of cutting-edge science and technology and is also an important guarantee for national defense and security. Silicon carbide fiber-reinforced silicon carbide （SiC_f/SiC） composites have been developed as promising structural materials that are applied in the hot-end components of high thrust-to-weight ratio aeroengines， due to their high temperature capability， high strength， low density， high thermal shock resistance， etc. The typical service environment of high-temperature structural components in the new generation of high thrust-to-weight ratio aeroengines is extremely harsh， with the gas-side wall temperature reaching up to 1500 ℃； however， the reliable service temperature of the third generation of SiC_f/SiC composites is about 1350-1400 ℃. Therefore， it is necessary to apply a thermal/environmental barrier coating （T/EBC） system with high temperature resistance， low thermal conductivity， thermal expansion matching the matrix， and excellent corrosion resistance， which is expected to provide both thermal protection and gas corrosion resistance for the SiC_f/SiC composites. Rare earth oxide ceramic materials， such as rare earth phosphates， tantalates， hafnates， zirconates， aluminates， and pure rare earth oxides， exhibit high average atomic weight， weak atomic bonds， complex crystal structure， and high concentration of oxygen vacancies， etc. These properties fulfill the necessary requirements for protective coating materials， making them highly promising candidates for T/EBC applications and a key focus of current research.In this paper， the roadmap of development on T/EBC systems as well as various rare earth oxide ceramics is reviewed. Particularly， the thermal-mechanical and corrosion properties of rare earth oxide ceramics， such as elastic modulus， thermal expansion， thermal diffusivity， thermal conductivity， and corrosion resistance against CMAS melts， etc.， are comprehensively reviewed and discussed. Moreover， given that the thermal-mechanical properties and corrosion resistance of rare earth oxides are closely related to the type of rare earth elements， it is proposed that designing high-entropy rare earth oxides-based materials is a rational strategy to achieve a synergetic optimization of the thermal-mechanical properties and corrosion resistance of these materials. Specifically， by adjusting the ratio of various rare earth elements in high-entropy oxides， controlling the average size of ions in rare earth oxides， and comprehensively considering the thermophysical and corrosion resistance properties of various rare earth elements， the performance of the material can be flexibly modified， which further promotes their application in the next-generation T/EBC coating system.At last， by reviewing the current research stage， we propose that the future development directions of the next generation turbine components of aero-engines highly rely on the multi-level design and whole-process preparation technology of high-quality coatings， including the efficient screening of coating materials， the innovative architectural design and microstructure modulation for coatings， advanced coating spraying technology， and the discovery of new mechanisms to slow down the corrosion and damage rate of coatings under thermal-oxidation coupled environment， etc.， especially for the application of new T/EBC coatings at temperatures above 1500 ℃. These research and advanced technologies are expected to generate new breakthroughs in the development of T/EBC for high-temperature structural components made of SiC_f/SiC composites in next-generation aero-engines.

Thin-walled specimens of DD6 single-crystal superalloy with varying thicknesses are fabricated using the Bridgman method. An investigation is carried out to examine the influence of cross-sectional size on the stress-rupture properties of these thin-walled specimens under the conditions of 980 ℃/250 MPa and 1100 ℃/130 MPa. The results reveal that a thin-walled phenomenon occurs in specimens with a thickness less than 1.0 mm at 980 ℃/250 MPa and less than 1.5 mm at 1100 ℃/130 MPa. This thin-walled becomes more pronounced at elevated temperatures. The reduction in the effective loading area， which is attributed to oxidation and internal nitridation， serves as the primary factor contributing to the decline in the stress-rupture properties of thin-walled specimens. Based on the relationship between creep properties and microstructure， a concept of the thin-wall effect coefficient for single-crystal superalloys has been proposed. By utilizing specific surface area as a crucial intermediate variable， this method facilitates the extrapolation of the creep life for thin-walled components.

The cooling process following solution heat treatment significantly influences the microstructure and mechanical properties of powder metallurgy superalloy turbine disks. This study investigates the effects of air-forced cooling process parameters， including gas flow rate， air pipe diameter， and disk rotation， on the temperature distribution and cooling rate of turbine disk billets.The results reveal that an increase in the gas flow rate enhances the surface heat transfer of the turbine disk billet， creating a larger temperature gradient and achieving a higher cooling rate. When the gas flow rate remains constant， reducing the air pipe diameter leads to an increase in the local gas flow velocity， thereby strengthening the surface heat convection and raising the cooling rate. During rotation， the internal temperature gradient of the disk is reduced， resulting in a more uniform temperature distribution.The optimized air-forced cooling parameters， namely a gas flow rate of 240 m/s， an air pipe diameter of 10 mm， and disk rotation， are validated through experiments. After heat treatment， the grain size is uniformly distributed， measuring ASTM 7.5-8. The closer to the surface of the turbine disk billet， the higher the cooling rate， the finer the γ' phase， and the better the creep performance. Conversely， the core of the turbine disk billet has the lowest cooling rate， a coarser γ' phase size， and relatively poor creep performance.The grain size and creep properties of turbine disk billets quenched by air-forced cooling are comparable to those quenched by conventional oil cooling. Moreover， the creep plastic elongation at 68 h during creep is superior to that of oil-cooled quenching. Therefore， air-forced cooling quenching holds great promise as a turbine disk preparation process.

To clarify the effect of composition optimization on the hot corrosion behavior of powder metallurgy superalloys， a new powder metallurgy superalloy （hereinafter referred to as the new alloy） and FGH96 superalloy are selected as research objects. Gas hot corrosion and salt-coated hot corrosion tests are carried out at 700， 750 ℃， and 800 ℃， and the hot corrosion behavior are analyzed by X-ray diffraction （XRD）， scanning electron microscopy （SEM）， and electron probe micro analysis （EPMA）. The results show that the gas hot corrosion mechanism for both alloys is accelerated oxidation， while the salt-coated hot corrosion mechanism involves the synergistic effect of oxidation and sulfidation. Compared with the FGH96 alloy， the new alloy exhibits superior hot corrosion resistance， particularly at 800 ℃. This phenomenon is mainly attributed to the increasing contents of Co and Al element in the new alloy. The high Co and Al contents promote the rapid formation of continuous and dense Cr₂O₃ and Al₂O₃ scales on the alloy surface. Moreover， the high Co content suppresses the internal oxidation of Al and reduces the inward diffusion of sulfur through the third-element effect， resulting in a complete and continuous Al₂O₃ scale. This effectively protects the alloy substrate and reduces the oxidation and sulfidation rates of the alloy.

Ti-Fe-O alloy with excellent comprehensive mechanical properties is prepared using resource rich Fe₂O₃ as a strengthening agent and pure Ti powder as raw material， based on ball milling powder mixing， electric field assisted hot pressing sintering technology， and hot rolling process. The impacts of Fe₂O₃ content and the particle size of Ti powder on the microstructure and quasi-tatic tensile properties of the Ti-Fe-O alloys is investigated. The research reveals that an increase in Fe₂O₃ content and a decrease in Ti powder size facilitate the formation of the β phase and refine the α phase grains within the alloy. Hot rolling leads to a significant enhancement in the comprehensive mechanical properties of Ti-Fe-O alloys. The strength improvement is attributed to the interstitial solid-solution strengthening by O elements， grain refinement strengthening resulting from the refinement of the α phase， and the precipitation strengthening of nano-scale acicular secondary α phase within the β phase. Under the condition where the pure Ti particle size ranges from 15 μm to 45 μm （D₃₀）， the as-rolled Ti-0.71%Fe₂O₃ （Ti-0.58Fe-0.29O） and Ti-1.43% Fe₂O₃（Ti-1.08Fe-0.62O） alloys achieve an excellent strength-plasticity matching effect. Their tensile strengths and elongations at break reach 975 MPa with 20.6% elongation and 1128 MPa with 18.4% elongation， respectively.

The effect of solution temperatures，aging temperatures and aging time on the microstructure and mechanical properties of novel high-strength Ti-B25 titanium alloy is investigated by means of optical microscope，scanning electron microscope and electron backscatter diffraction. The results show that the microstructure of Ti-B25 titanium alloy consists of equiaxed primary α phase （α_p） and β matrix after solution treatment. As the solution temperature increases，the volume fraction and size of α_p phase gradually decrease，accompanied by the simultaneous deterioration of strength and ductility of the alloy. When the solution temperature is 780 ℃ and 800 ℃，with the increase of aging temperature，the secondary α phase （α_s） coarsens and decreases in volume fraction，causing a decrease in strength and an increase in ductility. At the solution temperature of 800 ℃ and aging temperature of 600 ℃，with the increase of aging time，the α_s phase continuously coarsens，and the volume fraction of α_s phase increases firstly and then decreases，resulting in an increase and then a decrease in the strength of the alloy，but little change in the ductility. After solution and aging treatment at 800 ℃/1 h/AC+600 ℃/8 h/AC，the size and volume fraction of α_s phase achieve a good balance，and the alloy achieves the best balance between strength and ductility. The tensile strength and yield strength reach 1270 MPa and 1220 MPa，respectively，while the elongation and reduction of area are 15% and 49%. Therefore，the optimal heat treatment scheme of the alloy is determined to be 800 ℃/1 h/AC+600 ℃/8 h/AC. After the optimal heat treatment，the volume fraction and grain orientation of α and β phases in the Ti-B25 titanium alloy microstructure change significantly. The volume fraction of the α phase and the proportion of high angle grain boundaries increase obviously. The α phase texture transforms from T-type texture to B-type texture，〈11\overline{\mathrm{2}}0〉∥TD and 〈10\overline{\mathrm{1}}0〉∥AD fiber texture，while the β phase texture changes from cubic texture to〈111〉∥TD fiber texture，and the texture intensity of both phases is enhanced.

Laser cladding is widely used in additive manufacturing， damaged-surface repair， and surface modification of Ti-6Al-4V alloys. However， the performance optimization of laser-cladded layers on this alloy is still limited by several issues， including locally coarse grains， excessive residual tensile stress， and limited improvement in corrosion resistance. In this study， a novel process combining laser cladding with synchronous laser shock peening is proposed. Through this synchronous composite process， a laser-shock forging effect is generated， enabling simultaneous cladding layer fabrication and strengthening. This further refines the microstructure， enhances the mechanical properties， and improves the corrosion resistance of the cladding layer. The results show that the lamellar β-Ti phase and acicular martensitic α′-Ti phase in the cladding layer prepared by the composite process are significantly refined， forming an interwoven and dense basket-weave structure. The microhardness of the cladding layer increases from 360-405HV_0.2 to 470-530HV_0.2， indicating a remarkable strengthening effect. Meanwhile， the average friction coefficient decreases from 0.42 to 0.35， corresponding to a reduction of 16.67%， and the volume wear loss decreases by 25.93%， confirming the significant improvement in wear resistance of the cladding layer. In addition， the shock wave induced by laser shock processing effectively promotes the transformation of residual tensile stress into compressive stress. The maximum residual compressive stress reaches 390 MPa， and the stress distribution becomes more uniform. The corrosion potential （E_corr） of the cladding layer increases by 0.027 V， while the corrosion current density （i_corr） decreases by 8.71×10^-8 A·cm^-2， indicating that the corrosion resistance is significantly enhanced and that passivation behavior occurs more readily.

Cross wedge rolled Ti-6Al-4V （TC4） titanium alloy workpieces with a large cross-section reduction， often display surface necking and internal defects during the forming process. True stress-strain（ɛ） curves for TC4 titanium alloy are derived from hot compression tests conducted within a deformation temperature range of 800-950 ℃ and a strain rate （\dot{\epsilon }） range of 0.1-30 s⁻¹. An Arrhenius constitutive model， which includes strain compensation， and DMM （dynamic material model）-type processing maps are developed to analyze the deformation and defect evolution in cross-wedge rolling. The influence of rolling temperature and heating methods on process defects is thoroughly investigated. The results indicate that both the necking and internal defects of the rolled workpieces diminish as the experimental temperature rises， corroborating the precision of the processing maps and finite element simulations. Microstructure characterization and mechanical property tests reveal that the better surface and internal quality of rolled workpieces can be obtained by induction heating compared with resistance furnace heating. Workpieces rolled using induction heating at 900 ℃ show a tensile strength of 1073.18 MPa， while retaining a hardness of approximately 400HV. The mechanism for internal defects formation in rolled workpieces is the preferential nucleation of microscopic voids at β phase regions or α/β phase interfaces. These voids then undergo axial extension under applied stress， leading to a banded distribution of microscopic cracks.

To explore the effects of different surface treatment processes on the properties of rare earth magnesium alloys，this study employs Mg-Nd-Zn-Zr rare earth magnesium alloy as the research subject and conducts surface modification by using three processes： phosphate conversion treatment，direct electrophoresis treatment，and phosphate-electrophoresis composite treatment. The surface morphology，coating uniformity，coating adhesion and corrosion resistance of the treated samples are systematically evaluated by scanning electron microscopy （SEM），eddy current thickness gauge，pull-out adhesion tester，electrochemical techniques and salt spray test，respectively. The results show that the phosphate conversion treatment forms a thin coating with microscopic cracks on the surface；the coating formed by direct electrophoresis treatment has pores between the coating and the substrate；while the phosphate-electrophoresis composite coatings are closely combined with the substrate without obvious cracks or pores. The adhesion force between the phosphate-electrophoresis composite coatings and the substrate is the highest，mainly because the phosphate conversion treatment not only increases the surface roughness of the substrate，but also the microcracks on the surface are conducive to the penetration of the electrophoretic coating into the interior. The results of electrochemical and salt spray tests show that the corrosion current density of the phosphate-electrophoresis composite coatings is the lowest，the capacitive arc radius is the largest，and the surface morphology has no obvious change after 144 h of salt spray test，demonstrating excellent corrosion resistance and durability.