1. Introduction: The "Old Guard" of Permanent Magnets
Alnico (Aluminum-Nickel-Cobalt) magnets, first commercialized in the 1930s, are among the earliest mass-produced permanent magnets. Despite facing competition from ferrites (1950s) and rare-earth magnets (NdFeB, 1980s), Alnico remains indispensable in niche applications due to its unique combination of thermal stability, corrosion resistance, and mechanical durability. This analysis explores the core logic behind Alnico’s survival and evaluates its future market potential amid evolving technological demands.

1.Introduction
Alnico (Aluminum-Nickel-Cobalt) magnets, developed in the 1930s, are renowned for their high remanence (Br), excellent temperature stability, and corrosion resistance, with operational temperatures exceeding 600°C. Despite facing competition from rare-earth magnets (e.g., NdFeB) and ferrites, Alnico remains indispensable in high-temperature, high-stability applications such as aerospace, sensors, and precision instruments. This analysis explores future R&D directions—high coercivity, low cobalt, high performance, and cost reduction—and evaluates their industrialization potential.

1. Introduction to Alnico Magnets
Alnico (Aluminum-Nickel-Cobalt) magnets, developed in the 1930s, are among the earliest permanent magnets used in industrial applications. Composed primarily of aluminum (Al), nickel (Ni), cobalt (Co), iron (Fe), and trace elements like titanium (Ti) and copper (Cu), Alnico magnets exhibit high remanence (Br), low-temperature coefficients, and exceptional thermal stability, with operational temperatures exceeding 600°C.

Traditionally manufactured via casting or sintering, Alnico magnets were dominant in motors, sensors, and aerospace applications before being largely replaced by ferrite and rare-earth magnets (e.g., NdFeB, SmCo) due to cost and performance limitations. However, their cobalt content (5–12%) and nickel content (14–23%) have revived interest in recycling amid rising critical metal scarcity.

Alnico magnets, as important magnetic materials, are widely used in various fields. However, their production processes, especially melting and sintering, can generate significant pollutants. This paper first introduces the environmental production requirements for Alnico magnets, including compliance with national and international environmental standards, adoption of clean production technologies, and implementation of resource recycling and environmental management systems. Then, it focuses on the pollution emission control during the melting and sintering processes, covering pollutant types, emission limits, control technologies, and monitoring and management measures. Finally, it provides a summary and outlook to promote the sustainable development of the Alnico magnet production industry.

In the realm of high-temperature permanent magnets, NdFeB and Alnico magnets represent two crucial material types with distinct performance characteristics. With the advent of technological advancements in high-temperature NdFeB magnets, questions arise regarding their potential impact on the market share of Alnico magnets in high-temperature applications. This paper provides a comprehensive comparative analysis of the advantages and disadvantages of NdFeB and Alnico magnets, focusing on their temperature stability, magnetic properties, cost-effectiveness, environmental adaptability, and application scenarios. By examining recent technological breakthroughs and market trends, we aim to elucidate whether high-temperature NdFeB magnets will encroach upon the high-temperature application market of Alnico magnets and offer insights for engineers and designers in making informed selection decisions.

In high-temperature permanent magnet fields, Alnico and SmCo magnets are two crucial materials with distinct performance characteristics. This paper delves into their core competitive relationship, analyzing the selection criteria from multiple dimensions such as temperature stability, magnetic properties, cost-effectiveness, environmental adaptability, and application scenarios. Through a comprehensive comparison, it provides a scientific basis for engineers and designers to make informed decisions in practical applications.

Cobalt, a critical raw material for Alnico magnets, has experienced significant price volatility in recent years due to factors such as supply-demand dynamics, geopolitical tensions, and technological advancements. This paper examines the impact of cobalt price fluctuations on the Alnico magnet industry, focusing on cost pressures, production decisions, and market competitiveness. It also explores alternative solutions under high cobalt prices, including material substitution, technological innovation, and supply chain optimization, to provide insights for industry stakeholders in navigating market uncertainties.

Alnico magnets, once dominant in the permanent magnet market, have witnessed a continuous decline in market share since the late 20th century. This paper explores the core reasons behind this decline, including the rise of alternative materials, resource constraints, and technological limitations. It also examines the irreplaceability of Alnico magnets in specific high-end applications, such as aerospace, military, and extreme environment operations, due to their unique temperature stability and anti-demagnetization properties. The analysis concludes that while Alnico's market share may further shrink, its irreplaceability in niche markets will persist, driven by technological advancements and emerging applications.

Below is a comprehensive comparison of the four mainstream permanent magnets—Alnico, Ferrite, Neodymium Iron Boron (NdFeB), and Samarium Cobalt (SmCo)—covering their core properties, costs, temperature resistance, and application scenarios:

In scenarios where the magnetic performance requirements are relatively low, such as in magnetic teaching aids and crafts, commonly used Alnico magnet grades include Alnico 2 and Alnico 3. Below is a detailed introduction to these grades and their suitability for such applications:

Magnets play a crucial role in various industrial and consumer applications, with Alnico and ferrite magnets being two commonly used types. This paper conducts an in-depth comparative analysis of the cost-effectiveness of Alnico and ferrite magnets, focusing on their performance in low-to-medium-end ambient temperature scenarios. It explores the reasons behind the widespread use of ferrite magnets in such scenarios and proposes strategies for Alnico magnets to break through and expand their application areas.

Alnico magnets, composed primarily of aluminum (Al), nickel (Ni), and cobalt (Co), have long been valued in the medical device industry for their exceptional magnetic properties, temperature stability, and durability. In critical applications such as nuclear magnetic resonance imaging (MRI) components and medical probes, the performance and reliability of Alnico magnets are paramount. However, the unique environment within medical devices imposes stringent requirements on magnet purity and the absence of magnetic contamination (magnetic cleanliness). This article explores the specific demands placed on Alnico magnets in these applications, detailing why purity and magnetic cleanliness are essential and how they are achieved.