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Acta Metallurgica Slovaca
Number of Followers: 1  Open Access journalISSN (Print) 1335-1532 - ISSN (Online) 1338-1156 Published by SciCell s.r.o.  [5 journals]
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- PRELIMINARY INVESTIGATION INTO MECHANICAL PROPERTIES AND MICROSTRUCTURAL
BEHAVIOUR OF INCONEL ALLOY UNDER WELDED AND UNWELDED CONDITIONS
Authors: Saurabh Dewangan, Sharath Narayanan, Gurbaaz Singh Gill, Utkarsh Chadha
Pages: 5 - 9
Abstract: This work focusses on analysing mechanical properties and microscopic assessment into Inconel-718 plates in welded and unwelded conditions. Welding was performed by tungsten inert gas welding technique. Two mechanical tests such as tensile test and hardness were performed on both the types of plates to compare the properties of welded joint and unwelded plate. Although Inconel 718 possesses good weldability, the strength, ductility, and hardness of welded joint were reported lesser than these of Unwelded plate. The microstructural images revealed that metal carbides present in Inconel plate had reduced after welding. The ultimate tensile stress and elongation before breaking of welded joint were 16% and 72% lower than Unwelded plate. The fractography analysis of the ruptured part revealed that Unwelded plate possessed higher ductility than welded plate.
PubDate: 2023-03-23
DOI: 10.36547/ams.29.1.1664
Issue No: Vol. 29, No. 1 (2023)
- Effect of SiO2 Surface Oxidation Coating of Silicon Carbide Particles
Reinforcement on the Mechanical Properties of Al-2.5%Mg/xSiCp Developed by
Stir Casting Method
Authors: ABDULFATAI AMBALI, Olatunde Ajani Oyelaran, Bukola Olalekan Bolaji, Ibrahim Onuwe Abdulmalik, Olayiwola Abdulrafiu Suleiman, Usman Hamza Ibrahim
Pages: 10 - 16
Abstract: The literature revealed that composites developed through stir casting process suffer some limitations such as low wettability and insufficient bonding between the molten Al and SiCp and the formation of aluminium carbide (Al4C3) at the interface which degrades mechanical performances of the composites. To overcome these challenges, this study used magnesium for improved wettability, heat treatment of reinforcement particles (SiCp) and application of metallic (SiO2) coating on the SiCp before addition to melt to improve Al-SiCp wettability in the manufacture of Al-2.5%Mg/xSiCp composites. The SiCp coating reduce direct interaction and promote wetting between SiCp and molten Al to developed Al-2.5%Mg/xSiCp composites. The percentage weight of SiCp varied from 5 wt% to 20 wt% (uncoated and coated) at 5 % intervals. The mechanical properties tests were conducted to examined the effects of coating and variation of volume percentage of SiCp on the composites developed. The results obtained showed that the reinforced alloy with both uncoated and coated SiCp performed favorably well compared to the control sample with 0% SiCp. The improvement of interfacial strength was observed in the composites developed with coated SiCp as the coating of SiCp enhanced its diffusion with Al-2.5%Mg.
PubDate: 2023-03-23
DOI: 10.36547/ams.29.1.1692
Issue No: Vol. 29, No. 1 (2023)
- The improvement of tensile properties of low-carbon steels via short-time
intercritical annealing
Authors: Meymanat Sadat Mohsenzadeh
Pages: 17 - 21
Abstract: The effect of low volume fraction formation of martensite on the tensile properties of low carbon steel was evaluated. First, steel samples with ferrite-cementite microstructure were produced. The thermomechanical treatment used included austenitizing at 1000 °C and then quenching in ice brine solution, tempering the obtained martensitic structure for 1 h at 650 °C, 80% cold rolling, and re-tempering for 2 h at 650 °C. In order to form a low volume fraction of martensite, steel samples with ferrite-cementite microstructure were intercritically annealed for 30 seconds at 740 °C. As a result of intercritical annealing treatment, 6.2% martensite was formed. The results of tensile test showed that the formation of 6.2% martensite led to the elimination of yield point phenomenon and Lüders banding, decrease of yield stress and increase of true stress at maximum load, while true uniform strain did not change significantly. The work hardening rate also increased significantly. Based on the results of modeling of the flow behavior with the Holloman equation, the work hardening capability of the steel sample including ferrite-cementite decreased after a certain plastic strain, while the work hardening capacity remained constant with the formation of a low volume fraction of martensite in the microstructure.
PubDate: 2023-03-23
DOI: 10.36547/ams.29.1.1709
Issue No: Vol. 29, No. 1 (2023)
- EFFECT OF ULTRAFAST HEATING ON AISI 441 FERRITIC STAINLESS STEEL
Authors: Giulia Stornelli, Luciano Albini, Paolo Emilio Di Nunzio, Giulia Tiracorrendo, Bryan Ramiro Rodriguez Vargas, andrea di schino
Pages: 22 - 25
Abstract: The use of the ultrafast heating (UFH) heat treatment process attracted great attention in the last few years, following the requirements of CO2 emissions reduction. The effect of ultrafast heating (UFH) treatment an AISI 441 ferritic stainless steels is reported in this paper. Results show that a minimum temperature of 975 °C is required in order to achieve a fully recrystallized microstructure. The study highlights the effect of ultrarapid annealing on grain size evolution as a function of different adopted process parameters. The obtained microstructure is related to mechanical properties in terms of ultimate tensile stress and hardness.
PubDate: 2023-03-23
DOI: 10.36547/ams.29.1.1713
Issue No: Vol. 29, No. 1 (2023)
- CRITICAL ANALYSIS OF MATERIAL BEHAVIOUR IN WELDED PLATES OF AISI 0.2%-C
STEEL UNDER AS-WELDED, QUENCHED AND ANNEALED CONDITIONS
Authors: Saurabh Dewangan, Vedant Vinod Nemade, Kanad Harshal Nemade
Pages: 26 - 33
Abstract: AISI 1020 grade of steel is well known for its good combination of high strength and fair ductility. Therefore, it is widely demanded in construction sectors. It possesses a good weldability too in both arc and gas welding conditions. In the present work four pairs of AISI 1020-0.2%C steel plates were welded by shielded arc welding method. Except one welded plate, other three were heat treated. Based on the heat treating, three different physical conditions were achieved- water quenched, oil quenched and annealed. All the samples were tested for tensile strength, hardness, and microstructure. The annealed specimen has showed a significantly improved tensile strength of 439 MPa which is 85% higher than as-welded specimen. Water and oil quenched specimens showed lesser strength than that of as-welded specimen. With regard to hardness, there were two different observations. The as-welded and annealed specimens indicated the highest hardness at welded joint whereas the lower values were reported in base metal part. In contrary, the water and oil quenched specimens were harder in base metal zone as compared to welded zone. Both, strength, and hardness were found in good correlation with microstructural appearance of the plates.
PubDate: 2023-03-23
DOI: 10.36547/ams.29.1.1719
Issue No: Vol. 29, No. 1 (2023)
- Case study of advanced processed OFHC copper by dry sliding wear test
Authors: Robert Bidulsky, Jana Bidulská, Tibor Kvačkaj, Marco Actis Grande
Pages: 34 - 38
Abstract: The wear behaviour of copper material processed by ECAP (Equal Channel Angular Pressing) and orbital forging (OF) is presented in this study. Dry sliding wear tests were carried out for the wear behaviour of the investigated system. Oxygen-free high thermal conductivity (OFHC) copper was used for testing. The new combination of metal forming processes was used because of ease of fabrication. Additionally, wear rate, friction coefficient and wears mechanisms were observed. The friction resistance is caused by the destruction of the adhesion between surface asperities in metal friction. Moreover, increased asperity interactions connected with wear particle entrapment gradually increase the friction coefficient. These results show the metal forming process's positive influence in reducing interfacial adhesion and asperity deformation. Finally, the combinations of newly used advanced processing demonstrated excellent wear characteristics of copper.
PubDate: 2023-03-23
DOI: 10.36547/ams.29.1.1734
Issue No: Vol. 29, No. 1 (2023)
- ASSESSMENT OF TRIBOLOGICAL PROPERTIES OF STIR CAST Al6063 ALLOY REINFORCED
WITH OKABA COAL ASH
Authors: Jamiu Odusote, Adekunle Adeleke, Peter Ikubanni, Samuel Adeiza, Qudus Badrudeen, Olalekan Ogunniyi, Temitayo Ogedengbe
Pages: 39 - 43
Abstract: Composite are multi-phase materials made up of matrix and reinforcement. This paper assesses the tribological property of Al6063 alloy (AMCs) reinforced with Okaba coal ash (OCA) using the stir casting method. By using a constant speed of 1000 rpm and two different loads (250 g and 750 g) on Taber wear apparatus, the tribological properties of the produced composite are contrasted with those of an unreinforced Al6063 alloy. The results show a reduction in wear index and the highest abrasion resistance at 4 wt.% coal ash at 500 g and 1000 rpm, as well as at 0, 2, and 6 wt.% with 8.688, 5.878, and 5.813 at 500g and 8.688, 5.878, 4.125, and 5.813 at 750g, respectively. Therefore, for all composite products compared to metal, there is an increase in abrasion resistance with a decrease in wear index, but this decreases when the load is increased to 750g, showing that the higher the load, the higher the wear index, which results in a reduction in abrasion resistance. Load is taken into greater consideration when using the AMCs manufactured in engineering applications. Additionally, SEM images revealed uniform distribution of the OCA reinforcement in the matrix alloy; thereby, improving its wear resistance.
PubDate: 2023-03-23
DOI: 10.36547/ams.29.1.1750
Issue No: Vol. 29, No. 1 (2023)
- High entropy coating from AlCoCrCuFeNi alloy, obtained by laser alloying
Authors: Vasyl' Girzhon, Vladyslav Yemelianchenko, Oleksandr Smolyakov
Pages: 44 - 49
Abstract: The structural-phase state of the Al-Co-Cr-Cu-Fe-Ni system high-entropy alloy obtained by laser alloying of technically pure aluminium surface layers was investigated by XRD, EDX and metallographic analyses. It is shown that in the process of laser alloying the formation of an an ordered multicomponent substitution solid solution based on BCC lattice took place, which is typical for high-entropy alloys. The process of heterogeneous crystallization of high-entropy alloys AlCoCrCuFeNi and Al3CoCrCuFeNi was modeled taking into account cooling rates of the melt. It is established that the formation of the obtained structure is a consequence of high cooling rates of the melt and high content of aluminum in the laser alloying zone. The microhardness of the alloyed surface was higher compared to high-entropy alloys of this system obtained under equilibrium conditions and was equal to 6.59 GPa. Additional reasons that may affect the high values of microhardness are analysed.
PubDate: 2023-03-23
DOI: 10.36547/ams.29.1.1710
Issue No: Vol. 29, No. 1 (2023)
- COMPARISON OF FINISHING MILLING STRATEGIES USING TOPOGRAPHY OF THE
MACHINED SURFACE
Authors: Ján Varga, Peter Ižol, Ľuboš Kaščák, Marek Vrabeľ, Andrzej Kubit
Pages: 50 - 55
Abstract: The plastics processing and injection molding industry is known for the fact that the future molded part contains a variety of geometric shapes and, in some cases, free surfaces. To produce these shapes, knowledge of CAM systems is required to enable the programmer to select the necessary milling strategies designed to achieve the best possible quality and dimensional accuracy. However, it is equally necessary to understand and appreciate the effect of each strategy and which strategy is best suited for a given type of surface. The paper compares finishing milling strategies by evaluating the topography of the machined surface. The material was AlCu4Mg aluminium alloy, where Constant-Z and Spiral strategy – circle-type finishing strategies were selected for the production process. Surface topography analysis was evaluated and compared at three different heights of the produced part with respect to the tool contact with the machined surface, which showed a variation in toolpaths and therefore also in the quality of machining. The surface topography results demonstrated the Constant Z strategy to be the more suitable strategy for producing the shaped surface, which achieved uniform toolpaths over the whole height of the part.
PubDate: 2023-03-23
DOI: 10.36547/ams.29.1.1763
Issue No: Vol. 29, No. 1 (2023)
