A brief summary of historic developments of Ti₂AlNb alloy based on orthorhombic phase is presented first. Combined with the specific application background of Ti₂AlNb alloy, the research status and application of powder metallurgy (PM) Ti₂AlNb alloys in connection with near net shaping technology using hot isostatic pressing (HIP) are mainly reviewed. Key issues such as preparation of PM Ti₂AlNb alloys, powder densification during HIP, forming of complex components and hot workability of PM Ti₂AlNb alloy were discussed. Future research directions are suggested in the summary section. The bulk of the paper is concerned with progress made in the last 15 years, especially in the last decade.

    Fine spherical metal powders are the main raw materials for metal additive manufacturing (3D printing). Gas atomization technology is an important method to produce fine spherical metal powders. From the perspectives of increasing fine powder yield, improving powder quality and developing new powder materials, the research status and development trend of gas atomization technology for preparation of feedstock powder used in metal additive manufacturing were analyzed. Those methods used for increasing fine powder yield during gas atomization were summarized, which were developed based on optimizing atomizer design, enhancing atomizing medium properties or improving melt characteristics. The formation mechanism of hollow particles during gas atomization was analyzed, and the control methods of hollow particles were proposed. The formation mechanism of satellite particles during gas atomization was analyzed, and the control methods of satellite particles were proposed. Metal-matrix-composite (MMC) particles were proposed for additive manufacturing of composite parts. The research progress on metal atomization methods coupled with particle co-injection for the preparation of MMC particles was briefly introduced.

    Powder metallurgy (PM) TiAl-based alloy can solve the problems associated with ingot metallurgy, such as composition segregation, coarse microstructure and shrinkage cavity. In this paper, recent progress of PM TiAl-based in termetallics in powders preparation, sintering, forming and heat treatment was reviewed. Some methods were introduced including cold crucible vacuum induction melting gas atomization (VIGA–CC), electrode induction melting gas atomization (EIGA), hot isostatic pressing (HIP). Furthermore, the research direction of PM TiAl-based intermetallics was pointed out.

    Spark plasma sintering (SPS) is a new type of powder metallurgy technology with the advantages of low temperature, short time and high efficiency. In this paper, the sintering mechanism, process advantages and equipment development of SPS technology are introduced in detail. The latest research results of SPS in light metal, superalloy, refractory metal, cemented carbide, ceramic material and high thermal conductivity material are reviewed. The development trend and prospects of SPS technology are prospected.

    Two kinds of water atomized pre-alloyed powders with high Si content were used as raw materials. The sintering temperature range was determined by DSC analysis. High chromium cast iron with high mechanical properties were prepared by super-solidus liquid phase sintering (SLPS). Optical microscopy and scanning electron microscopy were used to analyze the microstructure changes of high chromium cast iron, and the performance of two-component sintered high chromium cast iron was compared and analyzed. The results show that the alloys with similar composition, the alloy containing 1.48% of Si is hypoeutectic, and the alloy containing 3.23% of Si is a typical hypereutectic composition. Both carbides are short rods, evenly distributed at the grain boundary and the subgrain boundary. At the same time, Si atoms can be dissolved in austenite, which reduces the solubility of C and Cr atoms in austenite, which in turn affects the austenite stability. Finally, the two alloys get different matrix structures. Compared with the alloy containing 1.48% of Si, the mechanical properties of the alloy containing 3.23% of Si decreased. The hardness of the alloy containing 1.48% of Si is HRC56.5, the impact toughness is 9.59J/cm², the bending strength is 2208.98MPa. The hardness of the alloy containing 3.23% of Si is HRC48.5, the impact toughness is 2.73J/² ancmd the bending strength is 1664.28 MPa.

    Compared with traditional alloys, high entropy alloys have outstanding physical, magnetization, chemical and mechanical properties. In the past decades, high-entropy alloys have become a fast developing research direction in the field of materials science, and have a wide application prospect. The research progress, advantages and disadvantages of preparation methods of high-entropy alloys are reviewed, its organizational structure and excellent performance application are analyzed, and the future research directions are summarized.

    High-quality spherical refractory metal powder is the key raw material for the production of high-performance refractory metal components through advanced powder metallurgy manufacturing and processing technologies, such as hot isostatic pressing, thermal spraying, injection molding and 3D printing. At present, the preparation technologies of the spherical refractory metal powder mainly include physical chemistry method, plasma spheroidization method, plasma atomization method and plasma rotating electrode process. In this paper, the principles of these four types of powder producing methods and the physicochemical properties of refractory metal powders are reviewed, and the technical characteristics and advantages of these four types of powder producing methods are remarked, the future development strategies of the refractory powder producing technology are also pointed out.

    There is a great demand for hole making of composites in aerospace, in which the defects at exit of holes such as delamination, crack and burr are the main problems at present. In order to suppress the defects at hole exit, a new process of reverse helical milling was proposed. A special tool with special shape was designed and the mechanism of suppressing delamination was also analyzed for the new process. The corresponding schemes were proposed, the feasibility of which was verified by experiments for the hole-making demand of metal/composites laminated structures and composites components. During the experiment, the results were compared and analyzed by recording the process of producing and removing defects. The results show that the reverse helical milling can obviously improve the quality of the hole making by effectively suppressing the formation of the defects of the composites.

    In order to study the effect of surface coating time on electromagnetic properties and microwave absorbing properties, carbonyl iron was coated with SiO₂ by hydrolysis of tetraethyl orthosilicate (TEOS). The elements and chemical bonds of the samples were characterized by XRF and FT–IR, and the surface morphology of the samples was analyzed by TEM to determine the thickness of the coating. The electromagnetic parameters were measured by a vector network analyzer to study its absorbing properties. The results show that the surface coating thickness is about 40–60nm. With the coating time prolonged, the thickness of the coating layer gradually increases. After simulation, the absorption peak of the electromagnetic wave after coating is moved to a high frequency, band width (R_L≤–10dB) increases significantly. The sample coated for 2h has the smallest reflection loss, the lowest peak value is – 45.18dB, which shows good absorbing performance.

    As the development of bionic surface engineering technology, many excellent surface properties of micro-texture surface have been confirmed by more and more research, such as drag reduction and wear resistance. But its application and promotion have been limited by complex and inefficient manufacturing techniques. As an efficient and automatic processing method, CNC machining can effectively adapt to the processing of complex shape parts and meet the requirements of high precision. Aiming at the numerical control machining technology of blade micro-texture, a collisionfree tool axis generation method is proposed. The method first obtains a tool path curve by extracting a micro-texture model guide line or intersection line of offset surface of micro-texture surface and smooth blade surface. Then, at each tool point on the tool path curve, a local coordinate system and a reference plane are established according to certain rules. Next, in the reference plane, the oscillating region of the tool axis at the tool point is solved according to the blade interference condition, the machine rotation axis travel and tool parameters. Finally, the collision-free tool axis vector is generated according to the safest principle. Taking an impeller blade as an example, the NXOpen C++ secondary development technology and VERICUT simulation successfully verified the correctness of the collision-free tool axis generation method, and it provides technical support for the high-efficiency CNC machining of the blade micro-texture.

    This paper discusses the key technologies of the integration of design and manufacturing for aviation product, especially for the management of single source of aviation product data based on MBD, aviation product development business process modeling and optimization based on lean system engineering, aviation product development process control technology based on maturity model. The research of this paper accelerates the evolution of the development mode of complex product, and also improves the development ability of aviation industry.