Acknowledged as a highly versatile manufacturing technology, additive manufacturing holds the potential to transform traditional manufacturing practices in the future. This paper provides a comprehensive review of the latest processes for manufacturing multi-material structural components using additive manufacturing technologies. It discusses the most recent applications of these processes in the fields of automotive, aerospace, biomedical, and dental, and presents a systematic overview of commonly used methods in multi-material additive manufacturing.

Aluminum alloy is widely used in military, automobile, aerospace, electronics, electric power and other industries. With the continuous development of industry, the demand for lightweight, topology structure and integration of functions and structures is becoming increasingly strong. Traditional technology has been unable to meet the demand. Additive manufacturing has significant advantages in the integrated forming of complex components due to its direct forming, strong adaptability, and short manufacturing cycle. This article comprehensively reviews the research progress of additive manufacturing of aluminum alloys in recent years, with a focus on three additive manufacturing technologies which are wire and arc additive manufacturing, laser metal deposition and selective laser melting. It reviews the principles of the three technologies and the progress in recent years and summarizes the challenges faced by the additive manufacturing of aluminum alloys and their solutions.

This paper introduces an integrated design and manufacturing technology for L-band spiral antennas based on modified polyetheretherketone (PEEK). Initially, PEEK granules are blended with a laser activator for granulation and filamentation, and the antenna structure is fabricated using a fused deposition modeling (FDM) forming device. Subsequently, a pulsed infrared laser with a wavelength of 1064 nm is employed to etch spiral microstrips and feed network board circuit functional patterns on the surface of the formed PEEK material structure. Combined with electroless plating technology, metallization of the spiral lines on the PEEK surface and the feed network board circuitare achieved. Test results demonstrate that the integrated spiral antenna exhibits a standing wave ratio of 1.46 at a frequency of 1.575 GHz, with a gain of ≥-2 dBi within a range of ±70°, and a gain of ≥-4 dBi within a range of ±85°, essentially meeting the antenna specifications. The study indicates that this method holds research and application value for integrated products such as antennas and structural circuits.

This paper examines the interpretation and implementation of the “peaceful purposes” clause as it applies to military activities in outer space, analyzing its legal and political implications within the framework of international space law. The term “peaceful purposes” has long served as a cornerstone in treaties like the Outer Space Treaty (1967), designed to promote the peaceful use of outer space. However, ambiguities in its interpretation have led to diverging views among states, particularly as space activities increasingly intersect with military interests. This study investigates how the peaceful purposes principle has been interpreted in key legal instruments, evaluates how it applies to various military uses of outer space, and assesses the implications of these interpretations for international security and space governance. By examining recent state practices, doctrinal perspectives, and multilateral negotiations, the paper highlights the tension between the principle of non-aggression and the militarization of space, offering insights into potential pathways for legal reform and cooperation. The findings suggest that while the concept of “peaceful purposes” is rooted in non-hostile use, evolving geopolitical dynamics and technological advancements are challenging its application, necessitating clearer legal frameworks to balance national security interests with the pursuit of a sustainable and peaceful outer space environment.