The process parameters optimization in laser powder bed fusion (LPBF) technique have been studied extensively by using the volumetric energy input (E=P/(v.t.h)) equation, which includes the major build parameters; laser power (P), scan speed (v), layer thickness (t) and hatch spacing (h) [1-3]. Even though utilizing laser energy density to predict final properties of a specified materials is a good way to start, only considering this is not enough [4]. Researchers have generally focused on the effect of laser power and scan speed on the final properties [5-8]. This study indicates how major process parameters influence the physical and magnetic properties of LPBF-processed Fe-based amorphous/nanocrystalline composites ((Fe87.38Si6.85B2.54Cr2.46C0.77 (mass%)). The figure illustrates the magnetization (M)-magnetic field (H) loops corresponding sample microstructures fabricated by using same E (=60 J/mm3) and v (=1000 mm/s) and varying P, h and t (left corner). It is obvious that despite being printed with same energy density, changing h and t (Sample 1 and 2) or changing P and h (Sample 2, 3 and 4) led to the quite different results. It was found that bulk density improves as P increases, v, t and h decreases, i.e., high E is necessary, however, greater than 80 J/mm3 (due to the keyhole effect) and less than 45 J/mm3 (because of the insufficient energy input to the powder bed) causes either failing parts or large and high number of pores. Owing to the laser scanning nature, the microstructure evolves as molten pool (MP) and heat affected zones (HAZ) due to the high thermal gradient occurred between laser tracks [9]. MP form around the scans, having Fe2B nanograins mainly, whereas HAZ generally contains α-Fe(Si) and Fe3Si nanocrystalline clusters. The sizes and quantities of those nanocrystallites determine the magnetic properties. With same E (60 J/mm3), v (1000 mm/s) and t (50 µm), only changing P and h caused samples to have different saturation magnetization; 206 emu/gr (P: 90 W and h: 30 µm) and 150 emu/gr (P: 150 W and h: 50 µm) (Figure). 
**References:** [1] H. Gong, K. Rafi and H. Gu, Materials and Design, Vol. 86, p. 545-554 (2015). 
[2] S. Liu, H. Li and C. Qin, Materials and Design, Vol. 191, ID: 108642 (2020). 
[3] H. Gong, K. Rafi and H. Gu, Additive Manufacturing, Vol. 1, p. 87-98 (2014). 
[4] K. Prashanth, S. Scudino and T. Maity, Materials Research Letters, Vol. 5, p. 386-390 (2017). 
[5] S. Alleg, R. Drablia and N. Fenineche, Journal of Superconductivity and Novel Magnetism, Vol. 31, p. 3565-3577 (2018). 
[6] H. Jung, S. Choi and K. Prashanth, Materials and Design, Vol. 86, p. 703-708 (2015). 
[7] Y. Nam, B. Koo and M. Chang, Materials Letters, Vol. 261, ID: 127068 (2020). 
[8] D. Ouyang, W. Xing and N. Li, Additive Manufacturing, Vol. 23, p. 246-252 (2018). 
[9] C. Zhang, D. Ouyang and S. Pauly, Material Science and Engineering R, Vol. 145, ID: 100625 (2021). 

![](https://s3.eu-west-1.amazonaws.com/underline.prod/uploads/markdown_image/1/image/8a303fbd2fb2b87b8ef323cee9b2c17f.png) 
Figure: M-H loops and micrographs of the samples LPBF-processed with same E (=60 J/mm3) and v (=1000 mm/s).

Optimizing Laser Additive Manufacturing for Fe based Amorphous Magnetostrictive Materials

Fe-Co alloys have been ideal materials for various applications where high saturation magnetization (Ms), high permeability (µ) and low coercivity (Hc) are needed, especially for the applications where the minimization of mass and volume is a design parameter, such as aerospace industries [1-6]. In addition, their high Curie temperature makes them competitive candidates for high temperature applications [4]. In this study, in order to fully understand the compositional effect of Fe-Co alloys on their magnetic behaviour, Fe25Co75, Fe50Co50 and Fe75Co25 alloys were produced by using arc melting technique and characterized with the help of X-ray diffraction (XRD) analysis and superconducting quantum interference magnetometer (SQUID). XRD analysis indicated that all the samples were single phase (BCC), proving that oxidation did not occur during the manufacturing process. Furthermore, from their hysteresis loops, their magnetic saturations, remnant magnetizations and coercivities were found in the ranges 253-280 emu/gr, 2.06-6.15 emu/gr and 8.67-40.24 Oe, [4] respectively (Fig. 1). It was observed that as the % Co (wt.) content increases, saturation and remnant magnetization decreases, thus the Fe-rich alloys have higher magnetic properties. Also, after arc melting, stress-relief annealing was employed at 1073 K for 1 hr, resulting in reduction of the magnetic saturation (220-272 emu/gr), remnant magnetization (1.08-3.8 emu/gr) and coercivity (4.73-13.28 Oe) [5] due to the microstructural refinement, as it can be seen clearly in Fig.1. This study confirms that arc melting helps to improve the magnetic properties of Fe-Co alloys, because their magnetic properties is higher than the magnetic properties of those fabricated by mechanical alloying (Ms: 150-225 emu/gr, Hc: 25-70 Oe) [4] and cold rolling (Ms: 217.8 emu/gr, Hc: 87.7 Oe) [3]. Curie temperatures of the as-cast samples (1097-1181 K), are slightly lower than the values in the literature [5], also decreased slightly to the value range of 1071-1107 K after the heat treatment. By looking at Fig. 2, for the high temperature magnetic performances of as cast and annealed specimens, it can be seen that the annealed samples have a higher saturation magnetisation as a function of temperature. Further study has been undertaken to design and develop a new Fe-based amorphous alloy, with similar properties to Fe-Co alloys. The alloy of Fe45Co15B28Al10B2 was arc-melted followed by stress-relief annealing at 573 K for 1 hr to achieve the desired magnetic properties and amorphous morphology. Using DCS and temperature dependence magnetisation measurements up to 1000 K, the temperature dependence structural and magnetic behaviour was studied. DSC analysis indicates that the sample has glassy phase with the melting point of 1200 K and glass transition temperature of 800 K. Moreover, its Curie temperature was found as 940 K. Thus, this composition has promising results as a new soft magnetic material for high temperature applications.

**References:**

[1] S. Bergheul, A. Haddad, H. Tafat and M. Azzaz, “Magnetic , Microwave and Absorbing Properties Fe-Co of Alloy Synthesized by Mechnanical Alloying Process,” in Application of Contemporary Non-Destructive Testing in Engineering, Portoroz, Slovenia, 2005. [2] R. Fingers and G. Kozlowski, “Microstructure and magnetic properties of Fe–Co alloys,” Journal of Applied Physics, vol. 81, no. 8, pp. 4110-4111, 1997. [3] S. Honjo, S. Kikuchi, A. Sakuma, S. Ishio and J. Balachandran, “Preparation of magnetic Fe-Co alloy using texture controlled technique,” Journal of Magnetism and Magnetic Materials, vol. 465, pp. 64-69, 2018. [4] F. Sanchez-De Jesus, A. Bolarin-Miro, C. Cortes Escobedo, G. Torres-Villasenor and P. Vera-Serna, “Structural Analysis and Magnetic Properties of FeCo Alloys Obtained by Mechanical Alloying,” Journal of Metallurgy, vol. 2016, p. 8347063, 2016. [5] R. Sundar and S. Deevi, “Soft magnetic FeCo alloys: alloy development, processing, and properties,” International Materials Reviews, vol. 50, no. 3, pp. 157-192, 2005. [6] Y. Zhang, R. Ma, S. Feng, L. Cheng, P. Davies and P. Yu, “Microstructures and magnetic properties of Fe-35%Co alloy fabricated bymetal injection molding,” Journal of Magnetism and Magnetic Materials, vol. 497, p. 165982, 2020.

**Images:**

![](https://assets.underline.io/uploads/markdown_image/1/image/b10699c413116d6f4d080b35248523dd.jpg)

![](https://assets.underline.io/uploads/markdown_image/1/image/a2da2cf697ccf1f003fbfd7cb478a821.jpg)

 Heat treatment investigations of Fe-based alloys

JOA: Amorphous and Nanocrystalline Soft Magnets I

technical paper

#### Welcome to the 67th Annual Conference on Magnetism and Magnetic Materials, MMM 2022!

The Conference was held from October 31 to November 4 and offers both in-person and on-demand content.

MMM 2022 is sponsored jointly by AIP Publishing and the IEEE Magnetics Society. Members of the international scientific and engineering communities interested in recent developments in fundamental and applied magnetism are invited to attend and contribute to the technical sessions. The technical program will include invited and contributed papers in oral and poster sessions, invited symposia, a tutorial, and several special sessions. This Conference provides an outstanding opportunity for worldwide participants to meet their colleagues and collaborators and discuss developments in all areas of magnetism research.

<iframe width="560" height="315" src="https://s3.amazonaws.com/pf-user-files-01/u-59356/uploads/2022-11-02/un13zp7/MMM%20Welcome%20Video%20v5.mp4" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

For tickets to the event, please register at the following link: https://magnetism.org/registration

Please register for the MMM 2022 conference to join the event.

MMM 2022

This Conference provides an outstanding opportunity for worldwide participants to meet their colleagues and collaborators and discuss developments in all areas of magnetism research.

*Session Co-Chair: Tianxiang Nan, Tsinghua University*

*Session Co-Chair: Raju Ramanujan, Nanyang Technological University*

These on-demand presentations are available to view at your leisure.

JX: Soft Magnetic Alloys and Oxides

poster

INTERMAG 2021 Welcome Video



	
<figure class="video_container">
 <iframe src="https://screencast-o-matic.com/player/crflqFVnUpZ?v=6&ff=1&title=0&controls=1" width=640 height=360 frameborder="0" allowfullscreen="true"> </iframe>
</figure>

Want to buy a ticket? 

Register for INTERMAG 2021 here

[![](https://assets.underline.io/uploads/markdown_image/1/image/17ce76e7960db633258024eef8d6da7f.png)](https://intermag.org/register)

Got your ticket, but still can’t access the event?

Contact us and our team will look into it.

Merve Ozden

2

7

SHORT BIO

Presentations

Optimizing Laser Additive Manufacturing for Fe based Amorphous Magnetostrictive Materials

Heat treatment investigations of Fe-based alloys

Stay up to date with the latest Underline news!

PRESENTATIONS

CONFERENCES

COMPANY

RESOURCES