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Article

Combining Heat Treatment and High-Pressure Torsion to Enhance the Hardness and Corrosion Resistance of A356 Alloy

by
Mohamed Abdelgawad Gebril
1,*,
Mohd Zaidi Omar
2,
Intan Fadhlina Mohamed
2,
Norinsan Kamil Othman
3 and
Osama M. Irfan
4,5,*
1
Department of Mechanical Engineering, Faculty of Engineering, Benghazi University, Benghazi 16063, Libya
2
Department of Mechanical and Manufacturing Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Malaysia
3
Department of applied physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Malaysia
4
Department of Mechanical Engineering, College of Engineering, Qassim University, Buraydah 51452, Saudi Arabia
5
Mechanical Department, Beni Suef University, Beni Suef 62746, Egypt
*
Authors to whom correspondence should be addressed.
Metals 2022, 12(5), 853; https://doi.org/10.3390/met12050853
Submission received: 21 March 2022 / Revised: 6 May 2022 / Accepted: 12 May 2022 / Published: 17 May 2022
(This article belongs to the Special Issue Strengthening Mechanisms of Metals and Alloys)
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Versions Notes

Abstract

:
A356 aluminium alloy is subjected to heat treatment and high-pressure torsion (HPT) processing to investigate the impact of the combined treatments on the alloy’s microstructure refinement, corrosion resistance and hardness. The high-pressure torsion process was performed at room temperature for 0.75 and 5 turns. Subjecting the A356 Al alloy to a heat treatment and subsequent HPT processing produced a more refined microstructure, which has the effect of enhancing the alloy hardness and corrosion resistance under fragmentation and the homogenous redistribution of the intermetallic compounds and the Si particles. The results of the treatment show that there is a marked increase in hardness when imposing a strain from 61 HV to 198 HV on the A356 Al alloy, which has been HPTed and heat-treated for five turns. The polarisation curves show that there is a considerable improvement in the corrosion resistance rate of the alloy from 0.043 mm·year−1 for the A356 Al alloy sample to 0.003 mm·year−1 after five turns of HPT. In this work, the microstructure refinement resulted in the improvement of both the mechanical strength and corrosion resistance of the aluminium 356 alloy after heat treatment in comparison to the untreated alloy.

1. Introduction

Aluminium alloys are lightweight materials that are used in the automotive and aerospace industries instead of cast iron and steel. Because of their desirable properties, such as excellent castability, high strength, high thermal conductivity, low thermal expansion coefficient and good corrosion resistance, Al-Si cast alloys (300 series) are increasingly used in the manufacturing of engine components, such as pistons, cylinder heads, engine blocks and crankcases [1,2,3]. The cast alloy A356 Al is widely utilised in the manufacture of automotive powertrain components. For its propensity to improve castability, Si is a primary alloying element in the A356 Al alloy. However, because of its low solubility in aluminium, it precipitates as coarse flakes with sharp edges, compromising the alloy’s mechanical characteristics [1,4,5,6,7]. The microstructure of these casting alloys is dominated by α-Al dendrites surrounded by eutectic Si particles in the form of platelets or flakes, as well as some intermetallic phases, such as Fe-intermetallic phases, Mg2Si and Al2Cu.
The size, distribution and shape of the eutectic mixture components affect the mechanical properties of the alloys [8,9]. Within an aluminium matrix, Si and intermetallic compounds display cathodic behaviour, resulting in the development of micro-galvanic couples [10,11,12,13]. Pitting corrosion resistance can be improved by lowering the area ratio of Fe-intermetallic compounds and noble Si particles to a less noble Al matrix. In other words, a lower cathode to anode area ratio (Ac/Aa) lowers the corrosion current density and makes it easier to produce a protective layer [14,15]. The heat treatment of A356 Al alloy can be used to modify the eutectic Si particle and the morphology of various intermetallic compounds in order to improve the corrosion resistance by reducing micro-galvanic action [11,16,17] and increase the strength of the alloy by precipitating Mg2Si particles [18].
High-pressure torsion has been shown to be one of the most effective severe plastic deformation processes for achieving a more refined grain structure in a range of alloys [19,20,21,22,23,24,25]. Several studies have shown that the HPT process improves the mechanical properties of aluminium alloys [26,27,28], while other have looked into the impact of grain refinement on the corrosion performance of aluminium alloys [29,30,31,32,33,34,35]. However, there is little agreement on whether the HPT technique can improve the corrosion performance of Al-7Si-3.89Cu-3Ni [36], Al-Fe system [37] and Al-4 Si wt.% [38].
Furthermore, there is a scarcity of studies on the effects of combining heat treatment with the refining process and severe plastic deformation. Nguyen et al. [39] investigated the effect of Al-6wt.% Si to a combination of annealing heat treatment and cooling slope prior to processing by equal channel angular pressing (ECAP) on the hardness and wear resistance of the alloy. The hardness of semi-solid cast ECAP samples improved as a result of the findings. The effect of combining ECAP processing with heat treatment in improving the corrosion resistance of 6061 Al alloy was investigated by Nejadseyfi et al. [40]. The results showed that the ECAP process created a shallow and uniform corroded surface. Natori et al. [41] studied the effect of combining a semi-solid and the ECAP method on Al-7.14Si-0.4 Mg (wt.%) and the mechanical properties that formed. The research revealed that combining semi-solid casting with the ECAP process resulted in Si particle refinement, primary phase grain refinement and a reduction in the hardness difference between the primary phase and the eutectic phase. Several severe plastic deformation methods, including as ECAP and accumulative roll bonding [42,43,44,45], can be used to refine microstructures. The T6 heat treatment combined with high pressure torsion (HPT) can be an effective approach for obtaining highly refined microstructures [40]. However, little research has been conducted on the interaction of these two processes and, as a result, they have consequences on microstructure and corrosion resistance.
The effects of T6 heat treatment and subsequent HPT on the microstructure, hardness and corrosion resistance of A356 Al cast alloy are investigated in this work. This research is significant because it clarifies the impact of the heat treatment performed to change the form of flaky silicon particles prior to refinement by using severe plastic deformation processes.

2. Materials and Methods

The material used in this study was a commercial A356 Al-7Si-0.178Ti-0.126Fe-0.149Mg-0.01Cu-0.006Zn-0.002Mn-0.001Cr (wt.%) with initial ingot dimensions of 80 × 40 × 140 mm (width–thickness–length). The materials were supplied by Vistec Technology Services Sdn Bhd in the form of ingots and pieces. The specimens were prepared for T6 treatment, which was accomplished at 535 °C for 8 h, and then the samples were quenched in water. Following this, the samples were further aged at 180 °C for 3 h [46]. A wire-cutting electrical discharge machine (EDM) was used to cut the A356 Al alloy samples into rod shapes with a 10 mm diameter, and the rods were then sliced into disks with a 1 mm thickness. The applied pressure was 6.0 GPa with a 1 rpm rotation speed in the HPT process, which was carried out at room temperature for 0.75 and 5 turns. A field emission scanning electron microscope (FESEM, Zeiss, Oberkochen, Germany), a field emission transmission electron microscope (FETEM, JEOL, JEM-2100F, Tokyo, Japan) and an optical microscope were used to study the microstructure of the samples (OM, Olympus Corporation, Tokyo, Japan). A microhardness tester (Zwick, Germany; ZHV) was used to measure the microhardness with an applied load of 100 g and a dwell time of 15 s. Indentations were made in the eight radial directions, with each indentation having an equal distance from the centre of the disk to the edge of the disk, as shown in Figure 1. The measurements were taken as the average of three samples per case, and indentations were made in the eight radial directions, with each indentation having an equal distance from the centre of the disk to the edge of the disk, as shown in Figure 1.
The as-cast A356 Al alloy samples and HPT disks were ground with a silicon carbide paper (SiC) with grits ranging from 180 to 1200 before being polished to a mirror-like surface with 1 m of diamond paste before being evaluated for microstructure (Al2O3). The sample was then dipped for 15 s in a Keller solution, rinsed under running water, and dried by using a blower. The microstructure of the disks was assessed both in the centre and at the edges. To quantify the grain size, a quantitative metallography study was performed in accordance with ASTM E112. The width and length of the Si particles were measured using the Smart Tiffv2 software, with at least 220 particles considered in each case. The corrosion test was carried out at room temperature with a GAMRY 3.2 potentiostat in a naturally aerated 3.5 percent NaCl electrolyte solution in order to mimic a seawater environment [11,12]. After approximately 15 min of immersion in 3.5 percent NaCl, the potentiodynamic test was performed.
To analyse the surface appearance of the sample, immersion tests were carried out for ten days in a 3.5 wt. percent NaCl natural aerated solution. Each sample was adhered on a piece of epoxy that had been air-dried for 24 h. Before conducting each corrosion test, the samples were ground with up to 1200-grit SiC.

3. Results and Discussion

3.1. Microstructure Pre- and Post-Heat Treatment

Figure 2a depicts optical micrographs of an A356 Al alloy sample containing a dendritic-shaped primary α-Al phase surrounded by a coarse eutectic mixture. The dendritic primary grain is approximately 172 µm with a coarse Si particle. Figure 2b shows the enlarged morphology of a flake-like shape with sharp edges. Figure 2c shows the characteristics of the microstructure after the T6 heat treatment of the A356 Al alloy. The flaky Si particles were transformed into angular- to spherical-shaped crystals and showed the presence of intermetallic compounds after the application of the T6 solution heat treatment.

3.2. HPTed Microstructure after 0.75 Turn Pre- and Post-T6

Figure 3 shows the optical micrographs of the centre and the edge of the HPTed A356 Al alloy sample pre- and post-T6 after 0.75 turn.
These images were taken at two different locations: (a,c) were taken at the centre of the disk and (b,d) were taken close to the edge of the disk, as shown in Figure 3. The large primary α-Al phase grain size can be observed at the centre of the A356 Al alloy specimen, while the primary α-Al phase with the longitudinal shape can be seen at the edge of the sample due to applied strain. The size of the α-Al phase decreases at the disk edge under the imposed strain, as shown in Figure 3a,b. The original large and coarse A356 Al alloy primary α-Al phase and low shear strain imposed through 0.75 turn contribute to retention of the large α-Al phase in the A356 Al alloy sample. The Si particles are heterogeneously distributed in the Al matrix of the A356 Al alloy. Figure 3c,d shows the microstructure of the HPTed heat-treated A356 Al alloy after 0.75 turn. The Si particles at the edge of the heat-treated A356 Al alloy are heterogeneously distributed.

3.3. HPTed Microstructure after Five Turns Pre- and Post-T6

Figure 4 shows the mapping of the centre and the edge of the HPTed A356 Al alloy pre-T6 after five turns. In the HPT processing of the A356 Al alloy samples, the primary α-Al phase can be observed at the centre of the disk as shown in Figure 4a. The grain boundaries of α-Al phase are non-obviously at the edge due to the greater shear resulting from the higher number of turns; this produced the homogeneously and uniformly distributed Si particles shown in Figure 4b. Figure 4b shows the presence of relatively large eutectic Si particles at the edge of the disk of the A356 Al alloy. The eutectic Si particles are homogeneous within the aluminium matrix in the A356 Al alloy sample. The Si particles are fragmented into significantly smaller sizes.
Figure 5 shows the mapping of the centre and edge of the HPTed heat-treated A356 Al alloy sample under an applied pressure of 6.0 GPa after five turns. The samples subjected to the combined heat treatment and HPT process causes the fragmentation of the Si particles due to the high strain imposed on them. The fraction of small Si particles is considerably higher, and the microstructure is more homogeneously distributed. This is consistent with the findings made by [47]. The eutectic Si particles are more homogenously distributed in the heat-treated samples than in the untreated samples. The edges of the processed samples have a finer microstructure than the centre of the samples as a result of the greater torsional strain during the HPT process as shown in Figure 5b.
Figure 6 shows the mapping of the Si particles and intermetallic compounds at the centre and the edge of the HPTed heat-treated A356 Al alloy sample. The initial flaky Si particles in the A356 Al alloy sample are no longer present after processing, and the extensive breakage of the Si phases and intermetallic phases can be observed after the T6 heat treatment that was followed by high compression pressure and strain. These results indicate that the sample subjected to heat treatment before HPT processing has a strong effect on the size and dispersion of the large silicon particles after processing.
The imposition of higher strains on the A356 Al alloy during the HPT process via increased rotational turns causes the breakdown of the intermetallic compounds and the Si particles in the A356 Al alloy. This process, in consequence, reduces the average of the Si particles size and the homogeneous dispersion of the eutectic phase. The T6 heat treatment and the subsequent HPT process produced a more refined Si particle due to the fragmentation process that occurred during heat treatment as well as to the higher torsional straining during the HPT process.

3.4. Hardness of the HPT of the A356 Al Alloy Pre- and Post-T6

Figure 7 shows the average Vickers microhardness across the diameter of each A356 Al alloy sample pre/post T6 via HPT under 6.0 GPa through 0.75 and 5 turns. The difference in hardness was determined along the diameter of the disk with a constant 0.5 mm separation between each processed disk. A significant increase in the hardness of the A356 Al alloy is noted after the HPT process, although it should be emphasised that the increase in hardness at the edge of the disk is more pronounced than in the centre. Applying the HPT process to the A356 Al alloy significantly increases its initial hardness. The values of hardness are low in the centre of the disk at the beginning of the deformation, but increase with the increase in the applied strain. The variation in hardness is dependent upon the number of turns and the position from the centre to the edge of the disk. The increase in hardness is more apparent after 5 turns, in contrast to 0.75, and is more apparent through the centre to the edge. The figure also shows that the edge of the disk shows a homogeneous distribution of hardness values after 5 HPT, which causes enhanced hardness. After the heat treatment, brittle Si particles were broken up and turned into spheroids, which made them stronger and harder [48,49]. Moreover, with the increased number of HPT turns, the error bar of the average microhardness for the HPTed heat-treated A356 Al alloy sample became smaller, which indicates that the microstructural homogeneity of the HPTed heat-treated A356 Al alloy samples is further enhanced through more HPT revolutions. This outcome is consistent with the microstructure observed in Figure 3, Figure 4, Figure 5 and Figure 6, which shows that the eutectic Si particles and intermetallic compounds in the sample processed through 5 turns are smaller and more uniformly distributed than the sample subjected to a 0.75 turn of HPT processing. The hardness of the A356 Al alloy sample increased after 0.75 and 5 turns after being subjected to heat treatment and the subsequent HPT. The increase in hardness can be ascribed to the fragmentation and redistribution of both eutectic Si and intermetallic compounds, the increased dislocation density and the grain refinement resulting from the high strain induced during HPT processing. As mentioned above, a higher number of revolutions in the HPT process generate significant shear stress associated with a high dislocation density, which could be attributed to grain refinement as shown in Figure 8 and greater microhardness [26,47,50,51,52]. The combined T6 heat treatment and HPT processing resulted in the refinement of Si particles.

3.5. Corrosion Resistance of the HPTed A356 Al Alloy

3.5.1. Surface Morphology

Figure 9 shows the top and side view micrograph of the HPTed A356 Al alloy pre- and post-heat treatment. Figure 9a shows the surface micrograph of the A356 Al alloy before HPT processing, while Figure 9b shows the surface micrograph of the HPTed A356 Al alloy sample after five turns and immersion for ten days in 3.5% NaCl solution. The corrosion generally spread along with the eutectic phase as a result of localised corrosion, while the silicon particles and α-Al interface were not affected by the treatment [53,54]. The HPTed heat-treated samples show a smaller size and number of pits as well as the area around the pits than those within the A356 Al alloy sample and the HPT as-cast sample due to the distribution of the smaller cathodic particles after the T6 heat treatment and HPT processing. The presence of an area free of corrosion around the pits indicates that cathodic reaction occurs in the corrosion-free area, while the anodic reaction occurs within the pit due to the concentration of galvanic cells [49,55]. Figure 9b,d shows that, when the heat-treated sample is compared to the A356 Al alloy sample, the processed samples with a higher number of HPT turns have a less pitting surface. The higher number of HPT turns is associated with reduced Si-containing particles in the alloy, while a decrease in the cathodic area causes a decrease in the anodic current density; this eventually results in improved corrosion resistance [56,57].
Figure 9c shows the side view of the pitting corrosion sample of the A356 Al alloy. It is worth noting that the enlarged eutectic mixture phase leads to more extensive surface corrosion of the alloy. This finding indicates that the micro-galvanic cells between the cathodic high Si and Al matrix may contribute to the development of pitting corrosion in the high Si particles area. Figure 9c shows the pitting corrosion of the HPTed heat-treated A356 Al alloy sample after five turns of HPT processing. The difference in the area of the eutectic mixture phase, the depth of corrosion and the spread of eutectic Si particles and intermetallic compounds before and after HPT processing between the A356 Al alloy and HPTed heat-treated A356 Al alloy samples enhanced the corrosion resistance values shown in Figure 9c,d and Table 1. The reduced eutectic phase, as well as the redistribution and homogeneity of the eutectic phase, contribute to the reduction in the corrosion rate of the HPTed combined heat treatment of the A356 Al alloy sample, in contrast to those of the A356 Al alloy before HPT processing. The FESEM and microhardness measurements indicate that there is an apparent evolution in the microstructure homogeneity of the A356 Al alloy samples with higher turn numbers of HPT processing, where the size of Si particles is reduced, the intermetallic particles are broken down and the refined Si and intermetallic particles become more uniformly distributed within the eutectic matrix.

3.5.2. Potentiodynamic Test

Potentiodynamic polarization was carried out to evaluate the impact of eutectic phase refinement and the microstructure homogeneity resulting from HPT processing on the corrosion resistance of the A356 Al alloy. The electrochemical behaviour of the A356 Al alloy was investigated by exposing the samples to a corrosive environment at room temperature using a 3.5% NaCl electrolyte solution [58]. The Tafel extrapolation method was used to measure the rate of corrosion to establish the corrosion resistance of both the A356 Al alloy and the combination of the heat-treated A356 Al alloy and the HPT-processed (HPTed heat-treated) A356 Al alloy samples. Figure 10, which shows the polarization curves of the A356 Al alloy samples before and after HPT processing, is used as a basis to compare the samples. Based on the above curves, the estimated average corrosion potentials of both samples are almost similar, with only minor differences. The results also demonstrate that the lower corrosion rate after a combination of the T6 heat treatment and HPT process may be attributed to the modified shape of Si particles after the T6 heat treatment as well as the grain refinement and redistribution of eutectic phase after HPT processing. These may be associated with a reduced cathodic to anodic ratio. The 0.0424 mm.year−1 corrosion rate of the A356 Al alloy was reduced to 0.00205 mm.year−1 after five turns of HPT. With the fine-grained structure of the α-Al and the eutectic phase, as well as the higher grain boundaries, the concentration of chloride per grain boundary is reduced, lowering the current density [59,60]. This results in the formation of a more stable passive film, which enhances corrosion resistance. The results of this study are consistent with those made by [61,62,63,64]. This results in the formation of a more permanent and intact passivation coating, which improves corrosion resistance.
Metals 12 00853 g010 550
Figure 10. Polarization curves of the A356 Al alloy (as-cast) before and after HPT processing.
Figure 10. Polarization curves of the A356 Al alloy (as-cast) before and after HPT processing.
Metals 12 00853 g010
Table
Table 1. Average of the current density (Icorr), corrosion rate (CR) and polarization resistance (Rp).
Table 1. Average of the current density (Icorr), corrosion rate (CR) and polarization resistance (Rp).
SamplesEcorr (V)Icorr A/cm2Rp (Ω·cm2)Βc (V·Dec−1)Βa (V·Dec−1)CR (mm·Year−1)
As-cast−0.6983.894 × 10−65.212 × 1030.6420.05040.0424
As-cast T6, 0.75 turn−0.7081.021 × 10−62.977 × 1040.4210.03750.012
As-cast T6, 5 turns−0.7102.233 × 10−78.870 × 1040.3320.03540.00295

4. Conclusions

In this study, the effect of microstructural refinement on the corrosion resistance and hardness of the A356 Al alloy processed by a combination of the T6 heat treatment and HPT processing was investigated. The following conclusions were reached:
  • An ultrafine-microstructure hypoeutectic A356 Al alloy with a homogenous distribution of eutectic intermetallic and Si particles was achieved by combining heat treatment and HPT processing through five revolutions at room temperature.
  • The hardness of the hypoeutectic A356 Al alloy was significantly improved with the increasing number of HPT turns.
  • The corrosion resistance of the HPTed heat-treated A356 Al alloy sample was significantly enhanced due to the microstructure refinement and redistribution of the eutectic phase in the Al matrix, which resulted in a reduced galvanic potential difference. The HPTed A356 Al alloy has the lowest current density 2.233 × 10−7 A/cm2, due to the combination of heat treatment and HPT process. The favourable corrosion resistance was attributed to the refined microstructure and the redistribution of the eutectic phase that prevented the occurrences of micro-galvanic cells on the alloy surface’s protective layer.

Author Contributions

M.A.G. carried out the experimental works, analysis and writing under the supervision of M.Z.O., I.F.M., N.K.O. and O.M.I. All authors have read and agreed to the published version of the manuscript.

Funding

The APC was funded by the Deanship of Scientific Research, Qassim University, KSA. (This work was supported in part by GUP-2018-150 grant under Universiti Kebangsaan Malaysia for materials processing in Kyushu University, Japan).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Acknowledgments

The authors wish to express their gratitude to the Deanship of scientific Re-search, Qassim University for funding the publication of this work.

Conflicts of Interest

The authors declare no conflict of interest.

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Figure 1. Schematic illustration of the HPT disk and the location of the micrograph, hardness measurement and corrosion area.
Figure 1. Schematic illustration of the HPT disk and the location of the micrograph, hardness measurement and corrosion area.
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Figure 2. Microstructural features of the A356 Al alloy of (a) as-cast, (b) enlargement of eutectic Si and (c) eutectic Si after T6.
Figure 2. Microstructural features of the A356 Al alloy of (a) as-cast, (b) enlargement of eutectic Si and (c) eutectic Si after T6.
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Figure 3. Microstructure of the HPTed A356 Al alloy pre-T6 at the (a) centre and (b) edge, and post T6 at (c) centre and (d) the edge by 0.75 turns.
Figure 3. Microstructure of the HPTed A356 Al alloy pre-T6 at the (a) centre and (b) edge, and post T6 at (c) centre and (d) the edge by 0.75 turns.
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Figure 4. Mapping of the HPTed A356 Al alloy pre-T6 at the (a) centre and (b) edge by 5 turns.
Figure 4. Mapping of the HPTed A356 Al alloy pre-T6 at the (a) centre and (b) edge by 5 turns.
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Figure 5. Mapping of the HPTed A356 Al alloy post-T6 at the (a) centre and (b) edge by 5 turns.
Figure 5. Mapping of the HPTed A356 Al alloy post-T6 at the (a) centre and (b) edge by 5 turns.
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Figure 6. Mapping of the HPTed heat-treated as-cast A356 Al alloy (a) at the centre and (b) at the edge and alloying elements at the edge (c) Al, (d) Si, (e) Mg, (f) Fe, (g) Ti and (h) Cu, after 5 turns.
Figure 6. Mapping of the HPTed heat-treated as-cast A356 Al alloy (a) at the centre and (b) at the edge and alloying elements at the edge (c) Al, (d) Si, (e) Mg, (f) Fe, (g) Ti and (h) Cu, after 5 turns.
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Figure 7. Microhardness plotted against distance from the disk centre of the A356 Al alloy pre-T6 (A-C) and post-T6 heat treatment (H-T, A-C) after 0.75 and 5 turns.
Figure 7. Microhardness plotted against distance from the disk centre of the A356 Al alloy pre-T6 (A-C) and post-T6 heat treatment (H-T, A-C) after 0.75 and 5 turns.
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Figure 8. TEM ultrafine grains micrograph of the HPTed heat-treated A356 Al alloy sample.
Figure 8. TEM ultrafine grains micrograph of the HPTed heat-treated A356 Al alloy sample.
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Figure 9. Surface appearance of the (a) A356 Al alloy; (b) HPTed heat-treated A356 Al alloy; side view of the (c) A356 Al alloy and (d) HPTed heat-treated A356 Al alloy after immersion for 10 days.
Figure 9. Surface appearance of the (a) A356 Al alloy; (b) HPTed heat-treated A356 Al alloy; side view of the (c) A356 Al alloy and (d) HPTed heat-treated A356 Al alloy after immersion for 10 days.
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Gebril, M.A.; Omar, M.Z.; Mohamed, I.F.; Othman, N.K.; Irfan, O.M. Combining Heat Treatment and High-Pressure Torsion to Enhance the Hardness and Corrosion Resistance of A356 Alloy. Metals 2022, 12, 853. https://doi.org/10.3390/met12050853

AMA Style

Gebril MA, Omar MZ, Mohamed IF, Othman NK, Irfan OM. Combining Heat Treatment and High-Pressure Torsion to Enhance the Hardness and Corrosion Resistance of A356 Alloy. Metals. 2022; 12(5):853. https://doi.org/10.3390/met12050853

Chicago/Turabian Style

Gebril, Mohamed Abdelgawad, Mohd Zaidi Omar, Intan Fadhlina Mohamed, Norinsan Kamil Othman, and Osama M. Irfan. 2022. "Combining Heat Treatment and High-Pressure Torsion to Enhance the Hardness and Corrosion Resistance of A356 Alloy" Metals 12, no. 5: 853. https://doi.org/10.3390/met12050853

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