Research progress on the preparation of nickel powders by spray pyrolysis

【Objective】 Nickel powder is a fundamental raw material in powder metallurgy, its physical and chemical characteristics are inextricably linked to the chosen preparation process. Among various synthesis routes, spray pyrolysis has demonstrated significant advantages in producing high-quality nickel-based powders. This paper systematically reviews several primary preparation methods—including mechanical milling, chemical reduction, hydrogen reduction, electrolysis, carbonyl decomposition, chemical vapor deposition (CVD), hydrothermal/solvothermal methods, and thermal decomposition. The objective is to compare their respective processes and key parameters while providing a technical basis for the advancement of spray pyrolysis technology.
【Method】 A comparative study was performed to evaluate the mechanisms, advantages, and limitations of conventional nickel powder synthesis techniques. The research specifically focuses on the operational parameters of the spray pyrolysis method. It investigates the influence of diverse factors, such as atomization methods, precursor types, carrier gas compositions, additives, and reducing agents, on the final morphology and structural integrity of the nickel powder.
【Result】 The findings indicate that while traditional methods like electrolysis or mechanical milling offer specific economic benefits, spray pyrolysis is superior for generating ultra-fine, spherical powders with high compositional homogeneity. The choice of atomization method significantly dictates the initial droplet size and subsequent particle fineness. Furthermore, the chemical nature of the precursors influences the kinetics of thermal decomposition, while the precise balance of carrier gases and reducing agents determines the oxidation state and surface morphology. The strategic application of additives was also found to effectively mitigate particle agglomeration, thereby enhancing powder dispersibility.
【Conclusion】 The selection of a nickel powder preparation technique must balance performance requirements with production costs. Spray pyrolysis is a critical development direction for high-performance nickel-based materials due to its high controllability and process continuity. By fine-tuning the interplay of process parameters, customized microstructures can be achieved to meet specialized industrial needs. This review serves as a comprehensive reference for optimizing spray pyrolysis, facilitating technological upgrades in the industrial production of nickel-based powders.