MPa Ultimate Tensile Strength Research Articles

Effect of the processing route on the microstructure and mechanical behavior of superlight Mg-9Li-1Zn alloy via friction stir processing

In this study, the effect of the processing route using a friction stir processing (FSP) method on the microstructure and mechanical behavior of a Mg-9Li-1 Zn alloy was systematically investigated. In the FSP method, the odd-numbered (1st and 3rd) process directions and even-numbered (2nd and 4th) passes were alternated to distribute the strain throughout the whole processed zone uniformly. Consequently, the processed zone had a much more uniform microstructure and hardness distribution than the processed zone obtained using the conventional FSP method. Using this method, the grain size of a Mg-9Li-1 Zn sheet alloy was refined from ∼31 μm to ∼0.21 μm with uniformly distributed α and β phases. The processed alloy exhibited a high strength-ductility synergy with an ultimate tensile strength (UTS) of 220.1 MPa and total elongation of 70.0% at a strain rate of 10 −3 s − 1 , overwhelmingly higher than those of the base metal, 155.6 MPa in UTS and 36.0% in elongation. The in-situ SEM-DIC analysis and TEM observation demonstrated that such an outstanding ductility with moderate strength is caused by grain boundary sliding, the dominant deformation mechanism of the ultra-fine-grained sample after FSP. The processing route with reverse processing direction was proven to be efficient in producing the ultrafine grain size microstructure and improving the mechanical properties of superlight Mg-9Li-1 Zn alloy.

Fabrication, microstructure characterization and mechanical properties of B4C microparticles and SiC nanowires hybrid reinforced aluminum matrix composites

Due to the high modulus, high strength, low density, excellent wear resistance and good neutron absorption, the boron carbide (B 4 C) particle reinforced aluminum (Al) matrix composites have been widely applied in the aerospace, weaponry, transportation and neutron shielding fields. In response to the increasing requirement of better strength -ductility matching of B 4 C/Al composites, introducing a nano-scale reinforcement into the B 4 C/Al composites becomes an attractive research focus. In this work, the SiC nanowires were ball-milled with Al powders, and then the SiC/Al composite powders were mixed with B 4 C microparticles. Thus, the 15vol. % B 4 C/SiC/Al composites with different volume fractions of SiC nanowires were fabricated by hot-pressing sintering and hot extrusion. B 4 C microparticles and SiC nanowires are uniformly dispersed in the B 4 C/SiC/Al composites, while the introduced SiC nanowires effectively decrease the Al matrix grain sizes. B 4 C/SiC/Al composites produce the better strength-ductility matching than that of B 4 C/Al composites, while the 15vol. % B 4 C/SiC/Al composite with 1vol. % SiC nanowires achieved the best strength-ductility matching. It generates the 281.7 ± 2.7 MPa in yield strength, 351.2 ± 0.1 MPa in ultimate tensile strength and 5.9 ± 0.7% in failure elongation, which are increased by 18.2%, 15.1% and 13.5% compared to the B 4 C/Al composites. Uniformly dispersed B 4 C microparticles and SiC nanowires largely block the dislocation motions and improve the dislocation storage capacity, which results in a more significant hetero-deformation induced (HDI) hardening effect in the B 4 C/SiC/Al composites. Moreover, the B 4 C/Al interfacial transition regions with the added SiC nanowires becomes stronger, which can enhance the load transfer efficiency of the B 4 C/Al interfaces as a result of the existing dislocation hardening zones. In conclusion, it is a good strategy to combine the synergistic strengthening effect of micro-scale and nano-scale reinforcements in the metal matrix composites. • The hybrid reinforcements of B 4 C microparticles and SiC nanowires generate a synergistic strengthening effect on the mechanical properties of B 4 C/SiC/Al composites. • The yield strength, ultimate tensile strength and failure elongation of B 4 C/SiC/Al composites with 1vol. % SiC nanowires are increased by 18.2%, 15.1% and 13.5% respectively compared to those of the B 4 C/Al composites. • SiC nanowires increase the geometrically necessary dislocations densities in the B 4 C/SiC/Al composites, which contribute to the heteto-deformation induced hardening effect and load transfer efficiency of the B 4 C/Al interface.

A low-cost and high-performance casted titanium matrix composite with Cr3C2 additions

A low-cost, high performance TiC reinforced titanium matrix composite was successfully fabricated using an in situ reaction casting method. The results showed that the morphology and distribution of TiC in the microstructure were the more important factors affecting the properties of composites. And due to the second phase strengthening of the TiC and the Cr element solid solution strengthening for titanium matrix, it provides exceptionally high strength and toughness (1034.5 MPa ultimate tensile strength and 9.0 % elongation) for titanium structural components and increases extremely high hardness (50.4HRC) for titanium wear-resistant components. This study provides additional options for the application of low-cost titanium components.

Effect of rotating magnetic field on NiAl(Si) phase evolution and mechanical properties of special nickel brass

The rotating magnetic field (RMF) has been proven as one of effective method and widely used for solidification controlling of metallics materials. In this present study, a rotating magnetic field was applied during the solidification of special nickel brass, and corresponding effect on solidification microstructure and mechanical properties were investigated and revealed. Results demonstrated that the application of RMF greatly affects the lattice parameters of the synthesized NiAl(Si) phase. It also can be determined that the applied RMF can effectively eliminate the aggregation of the NiAl(Si) phase at grain boundaries, which is favorable and beneficial for homogenous distribution of NiAl(Si) phase. Additionally, the applied RMF also refines the brass matrix and induces the morphology evolution of the NiAl(Si) phase changing from bulk to spherical morphology. Accordingly, the enhanced mechanical properties with 627 MPa in ultimate tensile strength (UTS), 518 MPa in yield strength (YS) and 3.6% in elongation (EL) can be obtained under the RMF with optimal current intensity of 30 A, corresponding to the improvement of about 6.1%, 5.0% and 33.3% over the respective properties of the special nickel brass without applied RMF. In addition, underlying mechanisms for the effect of RMF on the solidification process of special nickel brass and evolution of NiAl(Si) phase, as well as the resultant mechanical properties was discussed and clarified. It is anticipated that this present study would provide a feasible and effective approach to tailor the solidification microstructure and mechanical properties of the commercial brass for industrial application.

Optimization of biocorrosion resistance and mechanical properties of PM Ti–XAl–2Fe–3Cu alloys by response surface methodology

In the current study, the biocorrosion resistance and mechanical properties of the Ti–XAl–2Fe–3Cu (wt%) (X = 6, 4, 2 wt%) alloy produced by powder compact extrusion of blended elemental powders were optimized by using the response surface methodology in order to gain the best combination of processing parameters. To run the optimization process, central composite design with three equal levels of oxygen, hydrogen and aluminum was used and, by employing ANOVA, the analysis of variance was implemented. The results showed that the content of aluminum has a significant effect on the microstructure, mechanical properties, biocorrosion resistance and fracture behavior of the extruded rods. The highest aluminum content corresponds to the highest alloy strength and biocorrosion resistance. This was due to the reduction of the lamella thickness and of the material colonies as the aluminum content increases. Also, by running the experimental and optimization tests, the mechanical properties resulted 1245 MPa in yield strength and 1340 MPa in ultimate tensile strength with 0.1 µAcm−2 in corrosion current.

Mechanical properties and biocorrosion behaviour of as-cast Zn-xCu-Sr alloys for cardiovascular bioabsorbable devices

ABSTRACT In this study, the mechanical and biocorrosion behavior of as-cast Zn-xCu-0.1Sr (x = 1, 2, and 3wt%) alloys for potential application was studied. The microstructure, mechanical properties, and in vitro degradation of Zn-xCu-0.1Sr alloys were investigated. The results show that as Cu content increased from 1.0 to 3.0wt%, the number of CuZn5 phases increased and the average grain size of CuZn5 phases increased from 6.96 μm to 10.92 μm. The 2wt% addition of Cu resulted in the best mechanical properties with 129.4 MPa in ultimate tensile strength and 108.4 MPa in yield strength. Furthermore, the higher corrosion rate was experienced in the alloys with higher Cu content after immersion. Zn-xCu-0.1Sr alloys all presented appropriate in vitro degradation rates in a basically uniform degradation mode. The strength, ductility and biocorrosion property exhibited by the Zn-2Cu-0.1Sr alloy compositions make it a promising candidate for cardiovascular stent applications.

A Novel Hydroforming Process by Combining Internal and External Pressures for High-Strength Steel Wheel Rims.

As one of the key safety components in motor vehicles, the steel wheel rim is commonly fabricated with the roll forming process. However, due to the varied cross-sections of the rim and the low formability of high-strength steel, it is difficult to produce thin-wall and defect-free wheel rims to realize the purpose of light weight. To solve these problems, a novel hydroforming process by combining internal and external pressures (HIEP) was proposed to produce thin-wall wheel rims in the current study. The designed initial tube with diameter between the maximum and minimum diameter of the wheel rim ensures dispersed deformation and effectively avoids local excessive thinning. During HIEP, a hydroforming process was performed with two successive stages: the external pressure and internal pressure stages. Theoretical analysis and finite element method (FEM) were jointly used to investigate the effect of process parameters on the wrinkling and thinning. With the optimized parameters for internal and external pressure, the wrinkling of wheel rims is prevented under compressive state during the external pressure forming stage. Additionally, HIEP was experimentally carried out with high-strength steel rims of 650 MPa ultimate tensile strength (UTS). Finally, wheel rims with weight reduction of 13% were produced successfully, which shows a uniform thickness distribution with a local maximum thinning ratio of 11.4%.

Microstructure, mechanical and corrosion properties of biodegradable Zn-Mg-Zr alloys for biomedical applications

• Biodegradable HR Zn-1Mg-xZr alloys are fabricated via alloying and hot-rolling. • HR Zn-1Mg-0.05Zr alloy shows YS of 218.0 MPa, UTS of 263.2 MPa, and EL of 12.1% • Hot-rolling enhances the YS, UTS, and EL due to the dynamic recrystallization. • HR Zn-1Mg-0.05Zr alloy possesses a degradation rate of 71 μm/y in Hanks’ solution. Zn-1Mg-xZr alloys were prepared via alloying with different Zr contents and hot-rolling, and their microstructures, mechanical properties, and corrosion behaviors were assessed systematically. The results indicated that the mechanical strength of as-cast and hot-rolled (HR) samples initially increased and subsequently decreased with increasing Zr addition. HR samples showed a substantial increase in yield strength (YS), ultimate tensile strength (UTS) and elongation (EL) compared with their as-cast counterparts. HR Zn-1Mg-0.05Zr alloy showed higher mechanical property matching (218.0 MPa for YS, 263.2 MPa for UTS, 12.1% for EL) and an appropriate corrosion rate of 455 μm/y in Hanks’ solution among the Zn-1Mg-xZr alloys for biomedical applications.

Optimization of matrix viscosity improves polypropylene fiber dispersion and properties of engineered cementitious composites

• PP fiber dispersion can be improved by tailoring ECC matrix viscosity using VMA. • At optimal state, PP-ECC attains 7 % tensile strain and 3.5 MPa tensile strength. • Adding VMA beyond optimal state lowers ECC’s tensile strength and ductility. Engineered cementitious composites (ECC) is a durable cementitious material with high tensile ductility and strain-hardening characteristics. Although considered as a cost-effective fiber for ECC, polypropylene (PP) fiber is reportedly difficult to disperse in mortar matrix due to its high aspect ratio and hydrophobicity. In this study, the matrix viscosity of a low-carbon ECC based on limestone calcined clay cement was tailored as a variable to improve PP fiber dispersion under a pre-determined mixing protocol. The effect of matrix viscosity on the composite fresh and hardened properties was investigated experimentally. Results suggested an optimal range of matrix viscosity (10.3–11.5 Pa‧s) favors the composite tensile strength and strain capacity at 28 days. At the optimal state with a 0.1 % viscosity modifying admixture (VMA)-to-binder mass ratio, PP-ECC achieved 7.0 % tensile strain capacity and 3.5 MPa ultimate tensile strength. When matrix viscosity falls outside the desired range, both ultimate tensile strength and strain capacity were diminished. By tailoring the VMA dosage, the matrix viscosity can be adjusted for desired fiber dispersion, workability, and mechanical properties. The findings of this study provide a technical reference for the practical design and application of PP-ECC.

Statistical and Experimental Analysis of the Mechanical Properties of Jute Fiber Reinforced Epoxy Composite for the Transfemoral Prosthesis Biocomposite Socket Applications

ABSTRACT This research aims to design and fabricate biocompatible sockets for transfemoral amputee patients using innovative composite materials. An innovative material is developed using nature-based fibers along with a polymer matrix for the application of socket fabrication. Natural fibers prevent allergic reactions in the skin that occur because of prolonged contact of the skin with the socket. Since natural-based fibers exhibit advantages like low cost, low density, biodegradable, and eco-friendly, they have the high potential to be an alternative material for socket preparation. In this research, jute fiber is used as a reinforcement material due to its good mechanical and thermal properties. The matrix used is an epoxy belonging to the polymer family that is well moisture-resistant and has low shrinkage properties. The socket castings are fabricated using a simple hand lay-up method. Lamination of the jute fiber reinforced epoxy composite (JFREC) has 53 MPa of Ultimate tensile strength (UTS) had higher UTS than the fibers of perlon or nyglass, spectralon, nylon, and cotton, and 18.30 GPa of stiffness range had higher than the fibers of perlon or nyglass, spectralon, nylon, cotton, and glass. The prepared composite samples compressive strength and impact strength tests are studied, which posses an excellent improvement of 82% in strength. In addition, they are subjected to moisture resistance studies, which show good resistance to both normal water and sea water. The fabricated prototype socket possesses some good characteristics and will be implemented for the prosthetics.

Correlation between microstructure and tensile properties of powder metallurgy Ti-6Nb-x(Fe or Mn) alloys

The individual addition of Nb, Fe, or Mn to Ti has been greatly studied, but their combined addition has been much less understood, especially for the Ti-Nb-Mn system. Moreover, the full potential of using powder metallurgy to reduce their manufacturing cost has not been properly exploited and, even though proposed for structural applications, rarely tensile properties were reported. In this study new powder metallurgy Ti‐6Nb‐x(Fe or Mn) alloys were produced and the correlation between their microstructure and tensile properties established. It was found that, for a similar addition of Nb, Mn is a stronger eutectoid β stabiliser compared to Fe leading to more refined lamellar structures and a greater amount of stabilised β phase. Accordingly, higher tensile properties (832–1050 MPa yield stress and 910–1080 MPa ultimate tensile strength) and lower ductility (6.3–1.7 %) were, thus, obtained in ternary Ti-Nb-Mn alloys compared to Ti-Nb-Fe alloys, but the actual stress/strain pairs and hardness are the compromise between the volumetric fraction of residual porosity (3.6–4.9 %), which increases with the amount of alloying elements, and the microstructural changes induced by actual chemical composition.

Mechanical property and microstructure of in-situ TiB/Ti composites via vacuum sintering and hot rolling

High-plasticity in-situ TiB/Ti matrix composites (TMCs) are fabricated by in-situ reaction between Ti and ZrB 2 powder during vacuum sintering followed by hot rolling. Uniform microstructure is observed in the TMCs with obvious grain refinement. Compared with pure titanium, the mean grain size of Ti-2.0 wt% ZrB 2 composite significantly decreases from 50.7 µm to 17.5 µm, decreasing by 65%. Accordingly, Ti-2.0 ZrB 2 composite displays outstanding mechanical properties of 734.6 MPa in ultimate tensile strength, 579.0 MPa in yield strength, 21.4% in elongation, while these values of pure Ti are 632.4 MPa, 507.0 MPa, and 14.2%, respectively. The strength improvement of TMCs can be mainly attributed to five parts: grain refinement, solid solution strengthening, load transfer mechanism, CTE mismatch between TiB and Ti matrix and the dislocation substructure hardening. Among them, dislocation substructure hardening (more than 50% of the total improvement) takes the dominant position in strength increment in the as-rolled TiB/Ti matrix composites. • In-situ TiB/Ti composites were synthesized by ZrB 2 additive via PM process. • Obvious grain refinement is found with grain size decreasing from 51 µm to 16 µm. • TiB/Ti composites show a balanced combination of good strength and high ductility. • Ti-2 wt% ZrB 2 sample has UTS of 734 MPa, YS of 579 MPa and EL. of 21%. • Strength increment caused by dislocation substructure hardening is ranged from 47.2 MPa to 116.6 MPa.

Microstructure and mechanical properties of crack - free Ni - based GH3536 superalloy fabricated by laser solid forming

Laser solid forming (LSF) was used to fabricate dense and crack-free specimens from solution-strengthened nickel-based superalloy GH3536 in this study. Tensile, and fatigue crack growth (FCG) testing was carried out in both horizontal and vertical build orientations with the condition at 25 °C and 500 °C. Three regions can be detected in the specimen: the additive manufacturing zone (AM), the heat affected zone (HAZ) and the substrate. M23C6 and M6C carbides were found in the specimens, only a small amount of hole defects was observed in the samples, and no cracks were found. The tensile test results show that the specimens have obvious anisotropy, and the horizontal specimens displayed higher strength (up to 855.3 MPa ultimate tensile strength at 25 °C). It is worth noting that there is no obvious anisotropy in the FCG rates of the specimens in different directions, and only when the ΔK is about 45–60 MPa m1/2, the FCG rates of the vertical specimens are higher. The increase in temperature will significantly reduce the tensile performance and increase the FCG rate of the specimens.

A newly developed Mg-Zn-Gd-Mn-Sr alloy for degradable implant applications: Influence of extrusion temperature on microstructure, mechanical properties and in vitro corrosion behavior

The object of this study is to investigate the influence of extrusion temperature on the microstructure, mechanical properties and in vitro corrosion behavior of Mg–2Zn–1Gd–0.4Mn–0.1Sr (ZGMS) alloy. The results show that as–extruded ZMGS alloy mainly contains α–Mg and Mg3Zn3Gd2 (W) phases, and the W phase is uniformly distributed in the Mg matrix. With decreasing extrusion temperature, the grain size is refined, and numerous nano–sized W particles dynamically precipitate during extrusion process. The mechanical properties of as–extruded experimental alloy is significantly improved with decreased extrusion temperature.This is owing to the effects of grain boundary strengthening, precipitation strengthening and dislocation strengthening. The experimental alloy exhibits the lowest corrosion rate and relatively uniform corrosion after extrusion at 360 °C. The corrosion products layer are mainly composed of Ca10(PO4)6(OH)2, Ca3(PO4)2 Mg(OH)2 and MgHPO4. The as–extruded alloy owns excellent mechanical properties (yield strength of 206.3 MPa ultimate tensile strength of 261.1 MPa and elongation of 27.3%) and corrosion rate (0.17 mg/cm2/day) after extruded at 360 °C. The alloy presents tremendous potential in degradable implant applications. Additionally, the relationship between microstructure and corrosion behavior was systematically discussed.

Upset bulging as a preforming operation for hot metal gas forming of 22MnB5 tubes

Hot Metal Gas Forming (HMGF) is a coupled process of gas forming and quenching of tubes. This process allows to obtain complex and accurate geometry due to the elimination of springback and high mechanical properties due to the formation of martensite, as a result, the weight of the parts can be reduced. HMGF is widely used in the aerospace and automotive industries to make critical parts from high hardenability steels such as 22MnB5. A typical hot stamped component has 1000 MPa yield stress and 1500 MPa ultimate tensile strength. The main challenge of HMGF process is a significant material thinning and cracking due to the biaxial tension stress state. The paper proposes a preforming method for increasing the forming limits of HMGF by the cold upset bulging of tubes by means of the additional volume of material in the deformation zone. This method allows to obtain one or several waves in the cross section of the tube, which helps to increase the minimum workpiece wall thickness after the forming process by more than 40% and to reduce a probability of the crack formation.

Microstructural evolution and strengthening mechanism of high-strength AlSi8.1 Mg1.4 alloy produced by selective laser melting

A high-strength AlSi8.1Mg1.4 aluminum alloy was specifically designed for selective laser melting (SLM) by doubling the Mg content of A357 alloy based on the rapid solidification characteristics of the SLM process. The alloy showed good processability with maximum density over casting alloy with the same composition. The microstructure of the as-built alloy was characterized by the formation of cell structure. The α-Al cells manifested GP zones/Mg-Si clusters. The yield strength (YS), ultimate tensile strength (UTS), and elongation to fracture of the as-built alloy were 341 ± 14 MPa, 518 ± 6 MPa, and 7.1 ± 0.4%, respectively. Due to the precipitation of β″ nanoparticles in α-Al cells, the strength of the SLM alloy was effectively improved after direct aging at 150 ℃ and 200 ℃, with a maximum YS of 446 ± 5 MPa and maximum UTS of 546 ± 1 MPa, which were much higher than those of Al-Si-based alloy produced by SLM. When the aging temperature exceeded 200 ℃, the strength of the alloys decreased rapidly, but the elongation increased significantly. Multiple strengthening mechanisms, including grain refinement, GP zones/Mg-Si clusters, and β″ nanoparticle precipitation contributed to the high strength of SLM AlSi8.1Mg1.4 alloy.

Effect of the Heat Input on Wire-Arc Additive Manufacturing of Invar 36 Alloy: Microstructure and Mechanical Properties

AbstractInvar, also known as FeNi36, is a material of great interest due to its unique properties, which makes it an excellent alternative for sectors such as tooling in aeronautics and aerospace. Its manufacture by means of wire arc additive manufacturing (WAAM) technology could extend its use. This paper aims to evaluate the comparison of two of the most widespread WAAM technologies: plasma arc welding (PAW) and gas metal arc welding (GMAW). This comparison is based on the analysis of wall geometry, metallography, and mechanical properties of the material produced by both technologies. The results show a slight increase in toughness and elongation before fracture and worse tensile strength data in the case of PAW, with average values of 485 MPa for ultimate tensile strength (UTS), 31% for elongation and 475 MPa, 40% in GMAW and PAW, respectively. All results gathered from the analysis show the possibility of successful manufacturing of Invar by means of WAAM technologies. The novelties presented in this paper allow us to establish relationships between the thermal input of the process itself and the mechanical and metallographic properties of the material produced.

Effect of Heat Treatment on Tensile Properties and Microstructure of Co-Free, Low Ni-10 Mo-1.2 Ti Maraging Steel.

Production of high-quality maraging steel is dependent not only on the production technology but also on the alloying design and heat treatment. In this work, cobalt-free, low nickel, molybdenum-containing maraging steel was produced by melting the raw materials in a vacuum induction melting furnace and then refining with a shielding gas electroslag remelting unit. The critical transformation temperatures of the investigated steel samples were determined experimentally by differential scanning calorimetry (DSC) analysis and theoretically aiding Thermo-Calc software. Types and chemical composition plus volume fraction and starting precipitation temperature of suggested constituents calculated with the aid of Thermo-Calc software. The microstructures of forged steel specimens that were heat-treated under several conditions were evaluated by X-ray diffraction (XRD), optical microscopy (OP), scanning electron microscopy (SEM), and electron backscattering (EBSD), in addition to transmission electron microscopy (TEM). The mechanical properties of the investigated steel specimens were evaluated by measuring the tensile strength properties and micro-hardness, furthermore, estimating their fracture surface using scanning electron microscopy at lower magnification. The metallographic results show that the microstructure of steel in aged conditions includes high-alloyed martensite and nickel-rich phase, in addition to the low-alloyed-retained-austenite, intermetallic compounds, and lavas-phase (MoCr). Furthermore, TEM and EBSD studies emphasized that the produced steel has high dislocation density with nano-sized precipitate with an average size of ~19 ± 1 nm. Moreover, the metallographic results show that the mentioned microstructure enhances the tensile properties by precipitation strengthening and the TRIP phenomenon. The tensile strength results show that the n-value of investigated steel passes two stages and is comparable with the n-value of TRIP-steel. Steel characterized by 2100 MPa ultimate tensile strength and uniform elongation of more than 7% can be produced by the investigated production routine and optimum heat treatment conditions.

Influence of aging treatment on the microstructure, mechanical properties and corrosion behavior of Al-Zn-Mg-Sc-Zr alloy

The precipitation behaviour, mechanical properties and corrosion performance of an Al-Zn-Mg-Sc-Zr alloy under one-stage aging (T6), two-stage aging (T74) and retrogression and re-aging (RRA) treatment were mainly investigated. For the RRA treatment, with increasing temperature and duration of retrogression, the grain interior precipitates (GIPs) gradually grew and changed from GP zones + η′ phases to η′ phases + η phases. In addition, the discontinuity of coarsened grain boundary precipitates (GBPs) significantly increased, and the width of precipitate free zones (PFZs) became broader. Consequently, progressive decrease in strength and hardness, and improved corrosion resistance of the alloy can be observed. Compared to conventional T6 and T74 treatments, a good balance of mechanical properties (168.5 HV for hardness, 547 MPa for ultimate tensile strength) and corrosion resistance can be obtained with retrogression treatment at 160 °C for 30 min. Moreover, research on the localized corrosion of the Al-Zn-Mg-Sc-Zr alloy showed that, at the initial stage of pitting corrosion, the Al matrix around the cathodic α-Al(Fe,Mn)Si particles was uniformly dissolved, leading to the detachment of the α-Al(Fe,Mn)Si particles from the matrix and the formation of pitting pits.

Artificial neural network approach for mechanical properties prediction of as-cast A380 aluminum alloy

In this study, the dataset of as-cast A380 aluminum alloy involving chemical composition, processing parameter and mechanical properties was experimentally established. On this basis, the relationship between four input variables of Fe/Mn ratio, Sr content, cooling rate and porosity content, and two outputs of ultimate tensile strength (UTS) and elongation (El) was linked by two artificial neural network (ANN) models for comparison: (1) back propagation - artificial neural network (BP-ANN) model, and (2) back propagation optimized by particle swarm optimization - artificial neural network (PSO-BP-ANN) model. The results showed that the established PSO-BP-ANN model has better reliability and prediction accuracy than BP-ANN model, for lower root mean square errors (RMSE), 6.19 MPa for UTS and 0.08% for El, and higher determination coefficient (R2), 0.9775 for UTS and 0.9798 for El, respectively. Sensitivity level analysis result by the preferable PSO-BP-ANN prediction model showed that the order of relative importance for UTS is Sr content, cooling rate, Fe/Mn ratio, and porosity content while the importance ranking for El is Sr content, Fe/Mn ratio, cooling rate, and porosity content. The research results and dataset in this work lay a foundation for the control of casting performance in industrial practice and for secondary development of mechanical properties prediction module in commercial casting software.