Tempering of high-coercivity Alnico alloys

Vasin, G. P.; Povolotskii, E. G.

doi:10.1007/bf00654794

Cited by 3 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The aim of this work is to compare the difference in microstructures and magnetic properties of samples before and after tempering, so sample A is untempered and sample B is tempered at 650 o C for 4 hours, 600 o C for 6 hours, and finally 550 o C for 10 hours. Note that multi-step tempering improves the magnetic properties more effectively than one step tempering [18].…”

Section: Methodsmentioning

confidence: 99%

On the evolution of Cu-Ni-rich bridges of Alnico alloys with tempering

Min

Liu

Jha

et al. 2016

Journal of Magnetism and Magnetic Materials

View full text Add to dashboard Cite

Tempering is a critical step in Alnico alloy processing, yet the effects of tempering on microstructure have not been well studied. Here we report these effects, and in particular the effects on the Cu-Ni bridges. Energy-dispersive X-ray spectroscopy (EDS) maps and line scans show that tempering changes the elemental distribution in the Cu-Ni bridges, but not the morphology and distribution of Cu-bridges. The Cu concentration in the Cu-Ni bridges increases after tempering while other element concentrations decrease, especially Ni and Al. Furthermore, tempering sharpens the Cu bridge boundaries. These effects are primarily related to the large 2C44/(C11-C12) ratio for Cu, largest of all elements in Alnico. In addition, the Ni-Cu loops around the α1 phases become inconspicuous with tempering. The diffusion of Fe and Co to the α1 phase during tempering, which increases the difference of saturation magnetization between the α1 and α2 phases, is observed by EDS. In summary, α1, α2 and Cu-bridges are concentrated with their major elements during tempering which improves the magnetic properties. The formation of these features formed through elemental diffusion is discussed via energy theories.

show abstract

Section: Methodsmentioning

confidence: 99%

On the evolution of Cu-Ni-rich bridges of Alnico alloys with tempering

Min

Liu

Jha

et al. 2016

Journal of Magnetism and Magnetic Materials

View full text Add to dashboard Cite

show abstract

“…Tempering, which is also known as low-temperature draw, is performed in the temperature range of 650-550 °C. Multistage tempering has shown to produce better magnetic properties when compared with single-step tempering, as shown in Figure 14d [96]. Generally, a low-temperature multistage draw is performed at 650 °C for 4 h, 600 °C for 6 h, and finally for about 1 h at 550 °C [1].…”

Section: Temperingmentioning

confidence: 99%

Additively Manufactured Alnico Permanent Magnet Materials—A Review

Dussa,

Joshi,

Sharma

et al. 2024

Magnetism

View full text Add to dashboard Cite

Additive manufacturing offers manufacturing flexibility for intricate components and also allows for precise control over the microstructure. This review paper explores the current state of the art in additive manufacturing techniques for Alnico permanent magnets, emphasizing the notable advantages and challenges associated with this innovative approach. Both the LPBF and L-DED processes have demonstrated promising results in fabricating Alnico with magnetic properties comparable with conventionally processed samples. The optimization of process parameters successfully reduced porosity and cracking in the LPBF processing of Alnico. The review further explored the significance of additive manufacturing process parameter optimization in managing the temperature gradient and solidification rate for a desired microstructure and enhanced magnetic properties. Other potential additive manufacturing methods suitable for the fabrication of Alnico were discussed, along with the challenges associated with the process. The insights provided also highlight how additive manufacturing holds the potential to replace post-processing techniques like solutionization, magnetic annealing, and tempering often necessary in Alnico production.

show abstract