PRODUCTION OF FeAlSiMn ELECTRICAL STEEL BY POWDER METALLURGY WITH THE ADDITION OF DIFFERENT ALLOYING ELEMENTS

Abstract

In our country, electrical materials containing the FeAISiMn alloy were produced by the powder metallurgy method, and the effects of different alloying elements on these electrical materials were investigated. Various alloying elements were added to improve the electrical and mechanical properties of the produced samples. The hot pressing method was used as the production technique. Before sintering, the powders were homogenized by mechanical alloying for 30 minutes. The sintering process was carried out at 1000 °C under a pressure of 35 MPa for 5 minutes in an argon atmosphere. Characterization tests of the produced samples were performed.

Description

[0001] PRODUCTION OF FeAISiMn ELECTRICAL STEEL BY POWDER METALLURGY WITH THE ADDITION OF DIFFERENT ALLOYING ELEMENTS

[0002] TECHNICAL FIELD

[0003] Electrical materials containing the FeAISiMn alloy, which are used in our country, were produced by the powder metallurgy method, and the effects of different alloying elements on these electrical materials were investigated. Various alloying elements were added to improve the electrical and mechanical properties of the produced samples. The hot pressing method was used as the production technique. Prior to sintering, the powder mixture was homogenized by a mechanical alloying device for 30 minutes. The sintering process was carried out at 1000 °C at a pressure of 35 MPa for 5 minutes under an argon atmosphere. Characterization analyses of the produced samples were performed.

[0004] PRIOR TECHNICAL

[0005] The evolution and alloying of steel materials date back to ancient times. The earliest traces of steel, dating back to around 3000 BC, coincide with the beginning of the Iron Age.

[0006] In this period, products used in the manufacture of weapons, armor, and swords existed; however, due to the influence of the Bronze Age, they did not find widespread application. In later periods, with the decline of bronze and copper usage and the difficulties in finding ore, iron — and later steel — became the most widely used metals by humanity.

[0007] The era of mass steel production began in 1856 with the Bessemer process, developed by Henry Bessemer. In this process, liquid steel was produced in furnaces where air was blown from below, and the molten steel was transferred via pear-shaped converters. In 1865, another efficient method for steel production was developed: the Siemens-Martin process, in which burnt gas heat was utilized for heating and ore was converted into liquid or scrap steel inside a chamber. In the 1850s, the idea emerged that heat from electrical energy could aid in melting steel, laying the foundation of today’s electric arc furnace technology. By the 1930s, the development of cheap oxygen production enabled the replacement of bottom-blown systems. The development of steel production progressed rapidly during the 19th century with advancements in rolling mills and forging technologies. From this period onward, mass steel production accelerated to meet industrial demand. (Ayvaci, 2019).

[0008] Alloyed steels have continued to evolve according to changing needs. With continuous innovations in different steel classes — such as structural steels, tool steels, cold-hot work steels, high-speed steels, spring steels, stainless steels, and heat-resistant steels — the development of alloyed steels has persisted.

[0009] Microalloyed steels constitute an important subset, becoming widely used in the 1970s. The period between the 1970s and 1980s is considered the turning point for microalloyed steels.

[0010] During these years, fully controlled rolling processes were applied in countries such as West Germany, Japan, France, and Italy to maximize the mechanical properties of microalloyed steels. Low-carbon microalloyed steels became durable, tough, and highly weldable due to the formation of carbides and nitrides (Ayvaci, 2019).

[0011] Powder metallurgy (PM) refers to the production of metal powders and the consolidation of these powders into parts through mechanical and thermal processes. Today, powder metallurgy is widely used and is increasingly becoming an alternative to conventional manufacturing processes.

[0012] Literature studies have shown that iron-based materials produced by PM are widely used in industrial applications (Ayvaci, 2019). PM and particle-based methods allow near- net-shape part production, enabling the economical fabrication of high-quality, complex components.

[0013] Additionally, PM enables controlled placement of pores and phases, making it suitable for mass production and reducing concerns related to energy consumption, raw material usage, and manufacturing efficiency. Powder metallurgy is widely used in industries such as automotive. Products manufactured by this method include tungsten lamp filaments, gears, orthopedic implants, self-lubricating bearings, electrical contacts, office machine components, high- temperature filters, aircraft brake pads, jet engine parts, welding electrodes, catalysts, brazing tools, nuclear fuel elements, circuit boards, dental components, and many others.

[0014] The primary advantage of PM is not only cost but also the ability to manufacture complexshaped parts. Approximately 75-80% of PM products are used in the automotive industry. The majority of PM parts are iron-based (Qeviker, 1991 ; Gladman, 1997).

[0015] Some related studies in the literature include; Ayvaci, B. (2019). Investigation of the effect of pressing techniques on microstructure and mechanical properties of steels produced by powder metallurgy (Master’s thesis).

[0016] Qelik, E. (2009). Alternative binders in diamond cutting tools (PhD thesis, Firat University).

[0017] Qelik, Y. H., Kiligkap, E., & Yenigun, B. (2018). Effects of pressing pressure and B4C ratio on hardness and wear behavior in PM-produced aluminum matrix composites.

[0018] Qeviker, I. (1991 ). Microstructural characterization and microstructure-mechanical property relationships in microalloyed forging steels. Gladman, T., “The physical metallurgy of microalloyed steels”, The Institue of Materials, England, 1 , 341 (1997).

[0019] SUMMARY OF THE INVENTION

[0020] This invention aims to eliminate disadvantages related to production cost, material lifetime, the effect of alloying elements on electrical materials, and the manufacturability of electrical materials using powder metallurgy as described in prior technic. o Uretilen More efficient electrical materials can be produced by performing electrical and mechanical analyses on the manufactured components, enabling their potential use in our country. o By using domestic resources, high added value can be created, increasing national competitiveness in the field of electrical materials. o It enables the production of long-lasting, lower-cost electrical materials. o It can contribute to reducing the import of electrical materials and potentially increasing exports. o It contributes to the development of electrical materials technology across all regions of our country and to national advancement and international competitiveness. The magnetic hysteresis loops of the samples exhibit S-shaped curves with low remanence and low coercivity, demonstrating that all sintered samples are ferromagnetic at room temperature. The FeAISiMnCu alloy exhibits higher magnetization than the other alloys. Its maximum flux density reaches 1 .54 T. The FeAISiMnCu alloy requires a relatively lower magnetic field (H) for magnetization compared to FeAISiMnCr, FeAISiMnCo, and FeAISiMn alloys. Additionally, the BH hysteresis loop area of the FeAISiMnCu alloy is smaller, indicating lower hysteresis losses.

[0021] These soft magnetic materials can be widely used as electromagnetic cores, transformers, motors, generators, measuring device components, and similar applications.

[0022] Description of the Figures

[0023] Figure 1 . SEM images of sintered samples

[0024] Figure 2. Three-dimensional rotating powder mixing machine

[0025] Figure 3a. BH characteristics of the samples (large scale) Figure 3b. BH characteristics of the samples

[0026] DETAILED DESCRIPTION OF THE INVENTION

[0027] In this detailed description, the powder metallurgy-based production of FeAISiMn electrical steel with the addition of different alloying elements is explained solely to facilitate a better understanding of the invention and without imposing any limitation. In this study, the effects of different alloying elements on the mechanical and electrical properties of FeAISiMn alloy powders used as electrical materials will be investigated. Electrical materials based on the FeAISiMn alloy will be produced by powder metallurgy, and various alloying elements will be added to improve their mechanical and electrical properties.

[0028] Mechanical and electrical characterization analyses will be conducted on the produced samples. Key processing parameters — such as powder mixing, sintering temperature, and pressing pressure — which directly influence the performance of the electrical material, will be examined. Additionally, sintering temperature and the ratios of alloying additions will be varied to determine optimal production parameters.

[0029] The metal powders used in the production of electrical materials are Fe, Al, Si, Mn, Co, Ni, Cu, and Cr. These powders have a purity of approximately 99.9% and a particle size of 325 mesh. To ensure homogeneous mixing of the powders, an 88- type enclosed-chamber three-dimensional mixer with a 2 kg powder capacity was used (Liu et al., 2015). The chamber is sealed after loading to prevent interaction with the external environment. During operation, the chamber rotates 360° in all directions to ensure uniform blending.

[0030] The metal powders, prepared in specific ratios, were mixed in two stages in the three-dimensional mixer. The alloy powders were placed in a 1.2-liter airtight stainless-steel container and mixed for 20 minutes at 20 rpm. In the second stage, Co, Ni, Cu, and Cr powders were added. To ensure homogeneous distribution of the powders and prevent leakage from graphite molds, 1 wt.% Polyethylene Glycol (PEG) was added as a lubricant. The powders were then mixed for an additional 20 minutes together with chromium -coated steel balls. The purpose of using metal- coated balls is to prevent PEG agglomeration and ensure uniform concentration. After mixing, the prepared mixture was stored in an airtight plastic bag to prevent oxidation.

[0031] The hot pressing method was used in the production of the samples to achieve excellent microstructure and mechanical properties. Table 1 presents the chemical composition of the metal powder mixtures. Table 1. Chemical composition of the produced samples

Claims

CLAIMS1. The invention relates to the production of FeAISiMn electrical steel by powder metallurgy with the addition of different alloying elements, characterized by the following steps:- taking pure metal powders of Fe, Al, Si, Mn, Co, Ni, Cu, and Cr,- mixing the metal powders in a closed-type mixing chamber, in which the chamber rotates 360° in all directions to ensure thorough blending and obtain a homogeneous mixture,- using the metal powders consisting of Fe, Al, Si, and Mn at ratios of 85-95%, 1-5%, 2-10%, and 0.2-2%, respectively, Preferably adding additionally 0.1-10% Co or 0.1-10% Ni or 0.1-10% Cu or 0.1-10% Cr, and mixing these metal powders in two stages in a three- dimensional mixing machine,- placing the alloy powders preferably into a sealed stainless-steel container with a volume of 1 .2 liters,- mixing for preferably 20 minutes at a speed of 20 rpm,- adding Co, Ni, Cu, and Cr powders to the alloy powders in the second stage,- adding 1 wt.% Polyethylene Glycol (PEG) as a lubricant to the mixture to obtain a homogeneous distribution of the metal powders and to prevent the powders from leaking, even in small amounts, from the graphite molds,- subsequently mixing for an additional 20 minutes together with chromium-coated steel balls,- after mixing, transferring the prepared mixture into an airtight, sealed plastic bag to prevent oxidation,- performing hot pressing to obtain the microstructure and mechanical properties required to ensure a minimum strength value of 500 MPa for steel, contains the process steps.

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