T. Ibriksz

55514993800

Publications - 9

Examining Shape Dependence on Small Mild Steel Specimens during Heating Processes

Gusztáv Fekete T. Ibriksz F. Tancsics

Publication Name: Materials

Publication Date: 2024-08-01

Volume: 17

Issue: 16

Page Range: Unknown

Description:

With regard to the heating technology of small test specimens (D < 1 inch, i.e., 25.4 mm), only a limited amount of data and literature are available for making adequate technological decisions. Heating time of small geometric shapes is influenced by the technological parameters of the furnace, the temperature, the disposition technique in the furnace and the geometric characteristics of the workpiece. How to shorten heating time to achieve a suitable material structure is a vital question, while considerable energy is saved at the same time. Among the geometric characteristics, shape dependence is one of the important aspects that must be taken into account in terms of heating technology. Shape dependence is usually taken into account with empirically produced correction factors, which can result in significant oversizing of heating time, energy-wasting technology and material structure of insufficient fineness. In the course of our work, we investigated and compared the shape dependence of cylindrical and prismatic specimens with the same surface-to-volume ratios, which were combined with surface heat transfer analyses and geometric effect tests to formulate new approximate equations for determining heating time. As a result, we could mathematically derive a relationship between heating time, size and shape of the active surfaces, the correlation of which can shorten heating time by 20%. In addition, a shape factor (1.125) between cylinder and prismatic-shaped specimens was determined, which can be used with the new equation to calculate heating time for similar specimens. At last, a relationship is developed between the amount of heat that can be stored in the body during heat equalization and the complexity of the shape, which can be characterized through ratios depending on heating times and active surfaces in the function of total surface/volume ratio. Based on this relationship it can be determined more precisely when heat equalization occurs; therefore, shorter heating time can be achieved. In conclusion, with the help of this new method, optimal heating time for structural steel components, in the case of small cross-section and weight, can be determined.

Open Access: Yes

DOI: 10.3390/ma17163912

Determining the optimum heating time of small sized test specimen made from weldable mild steel

T. Ibriksz F. Tancsics

Publication Name: Iop Conference Series Materials Science and Engineering

Publication Date: 2020-08-25

Volume: 903

Issue: 1

Page Range: Unknown

Description:

The usage of CHT (Continuous Heating Transformations) diagrams for a given steel or equivalent grade, requires knowledge of heating temperature, average heating rate, and the heating time. Definition of these technological parameters are primarily based on the complex relationship system between the geometric, thermal parameters and the heating device. In our research, we mainly focused on those physical key parameters that can mostly influence the heating and transformation rate. These parameters provide realistic, usable data for analysing the process of thermal diffusion and FEA (Finite Element Analysis) tests. During analysis, an easy-to-use function relationship was determined for approaching the heating rate more precisely. This method allows handling the CHT charts easily, within a selected range, regarding weldable mild steels.

Open Access: Yes

DOI: 10.1088/1757-899X/903/1/012033

Effect of locally increased melted layer thickness on the mechanical properties of laser sintered tool steel parts

I. Fekete T. Ibriksz István Hatos András Lajos Nagy B. Kocsis H. Hargitai

Publication Name: Iop Conference Series Materials Science and Engineering

Publication Date: 2018-10-18

Volume: 426

Issue: 1

Page Range: Unknown

Description:

Additive technologies have several advantages over conventional manufacturing, such as the freedom of geometry of the products and internal structures. There are also some limitations and problems, deriving from stopping the process during the production. By restarting the process, the building often continues with a thicker starting layer due to the deposition of two or more layers. The effect of skipped melting of layers is investigated in this paper. Maraging steel powder (MS1) was used in direct metal laser sintering (DMLS) process to produce samples with increased thickness of melted layers. The layer thickness was increased in 20 μm steps up to 160 μm with 0.5 mm offset between the increased thickness layers. Porosity caused by the uneven melting was measured by optical microscope, mechanical tests were carried out to quantify the effect of skipped layers and fractured surfaces were observed under SEM. We have found that the yield strength and tensile strength are not affected if the layer thickness is slightly increased locally in the laser sintered part, while even a small increase in porosity greatly reduces the total elongation of the specimen. The decrease of impact energy due to the porosities shows similar correlation with the decrease of percentage elongation at break. However, the Charpy impact test is much more sensitive to layer skipping, the lack of melted layers lowers the impact strength significantly.

Open Access: Yes

DOI: 10.1088/1757-899X/426/1/012014

Investigating the relationship between the theoretical layer thickness of the graphite lubricant film and the Kudo's friction number in the case of forged parts.

T. Ibriksz F. Tancsics

Publication Name: Iop Conference Series Materials Science and Engineering

Publication Date: 2018-10-18

Volume: 426

Issue: 1

Page Range: Unknown

Description:

In case of numerical analysis of forged parts, it is important to specify the friction coefficient characterizing the lubrication conditions. In our paper we present a combined method of a known SU (Simple Upsetting) deformation with EDS (Energy Dispersive Spectroscopy), which shows the relationship between the Kudo's friction number (this friction model is applicable for metalworking processes which produces high surface pressure) and the theoretical layer thickness of the graphite film covering the sink cavity. The tests were accomplished considering the solids content of non-synthetically produced lubricant concentrates diluted to varying degrees.

Open Access: Yes

DOI: 10.1088/1757-899X/426/1/012047

Surface modification and wear properties of direct metal laser sintered hybrid tools used in moulds

I. Fekete J. G. Kovács T. Ibriksz Mária B. Maros István Hatos H. Hargitai

Publication Name: Journal of Mechanical Engineering

Publication Date: 2018-01-01

Volume: 64

Issue: 2

Page Range: 121-129

Description:

Injection moulding is one of the most productive plastic forming processes. Product development and the reduction of production time require new solutions in tooling design and manufacturing. Direct metal laser sintering (DMLS) allows moulds to be built with special cooling systems, which offer curved cooling lines that can follow the geometry of the part (conformal cooling). One disadvantage of DMLS, its high cost, can be dramatically reduced with the building of hybrid structures. With conventional tool steels as the base plate and only the special geometry of the part sintered on the top, the final geometry can be manufactured after sintering by conventional process technologies. We produced hybrid structures by direct metal laser sintering maraging steel (MS1) powder onto the surface of commercial mould steels and studied the effect of different heat treatments on porosity, tribological behaviour and the microstructure. The transition zone was also characterized.

Open Access: Yes

DOI: 10.5545/sv-jme.2017.4942

Detection of corrosion resistance of components in cyclic salt spray

Jan Mareček T. Ibriksz Vladimír Kročko Štefan Álló

Publication Name: Acta Universitatis Agriculturae Et Silviculturae Mendelianae Brunensis

Publication Date: 2015-01-01

Volume: 63

Issue: 1

Page Range: 9-13

Description:

The aim of this research is, to investigate the influence of two types of cyclic salt spray tests on parts surface treated with galvanizing. On the selected components was performed the method Zn-Ni surface treating on the bath line. Subsequently were the components embedded in the corrosion chamber, where was performed two types of cyclic salt test. In the first test was performed 4 hour salt spray, 8 hours drying, 60 hours condensation and 24 hours drying. Once cycle lasted 96 hours, and it was repeated 4 times. During the second test was performed 2 hours salt spray, 2 hours condensation. The cycle was repeated 4 times, that means 96 hours. After the cycle was performed 72 hours free relaxation in the corrosion chamber, on 20-25 °C temperature. As the research showed, after the cyclic salt spray was no red corrosion on the selected components. The white corrosion appeared only slightly.

Open Access: Yes

DOI: 10.11118/actaun201563010009

Reinforcing and compatibilizing effect of nano size montmorillonite on high density polyethylene - Polyamide 6 composites

T. Ibriksz H. Hargitai

Publication Name: Iccm International Conferences on Composite Materials

Publication Date: 2013-01-01

Volume: 2013-July

Issue: Unknown

Page Range: 8162-8169

Description:

No description provided

Open Access: Yes

DOI: DOI not available

Development of PA6/HDPE nanocomposite blends

T. Ibriksz János Stifter Endre Andersen H. Hargitai

Publication Name: Materials Science Forum

Publication Date: 2013-01-01

Volume: 729

Issue: Unknown

Page Range: 216-221

Description:

In our experiments polyamide 6/high density polyethylene blends (25/75 wt%) were produced and maleic anhydride grafted polyethylene was used as chemical coupling agent. To get finer microstructure and enhance the mechanical properties the blends were compounded by different nanostructured reinforcements. Two kinds of nanosilicate, the layered structure montmorillonite and the needle like sepiolite were applied in different concentrations and their effect on the mechanical and melting properties were examined. © (2013) Trans Tech Publications, Switzerland.

Open Access: Yes

DOI: 10.4028/www.scientific.net/MSF.729.216

Development of nanoclay reinforced HDPE/PA6 nanocomposites

T. Ibriksz H. Hargitai

Publication Name: Eccm 2012 Composites at Venice Proceedings of the 15th European Conference on Composite Materials

Publication Date: 2012-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

In our experiments HDPE/PA6 blends (75/25 wt%) were produced and maleic anhydride grafted polyethylene (PEgMA) was used as chemical coupling agent. To enhance the mechanical properties the blends were compounded with the layered structure montmorillonite (MMT) in different concentrations. The effect of PEgMA, MMT and their combination on the mechanical and melting properties were examined in this study.

Open Access: Yes

DOI: DOI not available