Brass Component Research Articles

Effect of cold-rolling and annealing temperature on microstructure, texture evolution and mechanical properties of FeCoCrNiMn high-entropy alloy

This study investigates the effects of cold rolling and annealing on the microstructure, texture, and mechanical properties of FeCoCrNiMn high-entropy alloys. Utilizing vacuum induction melting, the alloy was initially cast into ingots and hot-rolled into plates, which were subsequently cold-rolled to various thicknesses and annealed at different temperatures. Microstructural analyses were conducted using X-ray diffraction and electron backscatter diffraction techniques, revealing a persistent face-centered cubic structure across all conditions. The texture evolution demonstrated a shift from Copper and S components to dominant Goss and Brass components as cold rolling intensified, suggesting the formation of Brass-type texture in FeCoCrNiMn at high deformation. Mechanical testing showed that the alloy's yield and tensile strengths significantly increased with cold rolling, reaching optimum values at ∼66 % reduction. Annealing at 750 °C enhanced both strength and ductility, primarily through grain refinement and the formation of Σ3 annealing twin boundaries, which dominated the microstructure of recrystallized grains. The study confirms that the low stacking fault energy of the alloy facilitates the activation of twinning and transformation-induced plasticity mechanisms, crucial for the observed enhancements in mechanical properties.

Effect of stacking-fault energy on dynamic recrystallization, textural evolution, and strengthening mechanism of Fe−Mn based twinning-induced plasticity (TWIP) steels during friction-stir welding

This study aims to elucidate the effect of stacking fault energy (SFE) on the microstructural evolution and related hardening mechanisms of Fe−18Mn−0.6C−(0 and 1.5)Al and Fe−30Mn−3Al−3Si (wt.%) twinning−induced plasticity (TWIP) steels during friction stir welding (FSW) using a high−resolution electron backscattered diffractometer. With increasing SFE, the intensities of the Goss, CuT, and Brass components increased via active dynamic recrystallization (DRX) accompanied by twinning. The 30Mn weld, which had the highest SFE, exhibited the highest recrystallization fraction (94.8 %) and an increasing rate of hardness (40.9 %). This is because a higher SFE can enhance dislocation mobility, leading to an active rate of continuous DRX as well as discontinuous DRX. Consequently, the refinement of the recrystallized grains effectively assisted the hardening of the 30Mn weld after FSW. Hence, we concluded that SFE should be considered to improve the properties of TWIP steels after FSW.

In situ neutron diffraction study and electron microscopy analysis of microstructure and texture evolution during annealing of rolled CoCrFeNi alloy doped with 1 at.%C

In situ neutron diffraction studies of changes in the dislocation density, volume fraction of carbides, and crystallographic texture have been performed during annealing of a cold-rolled multi-principal element CoCrFeNi alloy doped with 1 at.%C. In addition, microstructures of the as-rolled and several annealed samples of this alloy have been investigated using electron microscopy-based techniques. It is found that cold rolling to a thickness reduction of 74% results in a brass-type rolling texture with a spread of orientations between the Goss and brass components and with a pronounced 〈111〉//ND fiber. The deformed microstructure is characterized by a high density of dislocations and shows large variations in deformation structures in regions of different crystallographic orientations. In particular, bundles of deformation twins and high frequencies of shear bands are observed in regions having orientations along the 〈111〉//ND fiber. Annealing at 700 °C–1000 °C leads to recovery and recrystallization, during which shear bands and regions of mixed orientations act as preferential nucleation sites for recrystallized grains. Precipitation of M23C6 particles also takes place during annealing. The particles retard boundary migration, thus slowing down recrystallization and restricting grain growth. The average size of recrystallized grains does not exceed 5 μm even after annealing at 1000 °C for 60 min. While rolling textures are retained in some annealed samples, other samples demonstrate distinct recrystallization textures with new texture components. The results obtained in this work are compared with the literature data for several carbon-doped face-centered cubic multi-principal element alloys and for a carbon-free CoCrFeNi alloy.

Effects of intermediate aging on the microstructure, strength and texture evolution of the Cu–Cr–Zr-Hf alloys

Cu-0.4Cr-0.2Zr-0.2Hf (wt%) alloy plates were prepared by cryogenic rolling and intermediate aging process. The effects of intermediate aging and cryogenic rolling on the microstructural, mechanical and textural evolutions were studied by X-ray diffraction, electron backscatter diffraction and transmission electron microscopy. The results show that the combination of cryogenic rolling and intermediate aging resulted in the formation of high-density dislocations, nanoscale deformation twins, deformation bands, and nano-precipitates in the Cu–Cr–Zr-Hf alloys. The nano-precipitates formed during the intermediate aging effectively increase the flow stress, and promote the formation of the nano-twins. Besides, the combination process can both reduce the fraction of the remnant grains and refine the width of remnant grains, promoting the homogeneous deformation of the Cu–Cr–Zr-Hf alloys. The reduction of the remnant grains decreases the Brass component, and increases the S component. The profuse nano-twins and Brass-type shear band contribute to the increase in the Y component.

Texture study of an AA5083 processed by Repetitive Corrugation and strengthening

5xxx series aluminum alloys are widely used due to their corrosion resistance and weldability. These alloys exhibit interesting behavior when subjected to severe plastic deformation (SPD). Different SPD techniques allow the processing of materials in sheet forms, such as Repetitive Corrugating and Straightening (RCS) and Cumulative Roll Bonding (ARB). In this work, sheets of the aluminum 5083 alloy were processed by RCS up to 2 passes. The objective was to study the microstructural evolution of the AA5083 under heat treatment and plastic deformation processes, with the aim of finding a good balance between the yield strength and ductility. The microstructure changes and the mechanical effects of the process were studied by X-ray diffraction, Inverse Pole Figures, EBSD, and tensile test. The results showed the obtention of characteristic recrystallization and deformation textures (cube and brass component); in particular, the brass component decreased to ∼10 % due to the RCS process. The first RCS pass obtained the best balance between yield strength-ductility (σy = 170 MPa and maximum elongation ∼ 8%). With the results obtained, it was concluded that the microstructure and the mechanical properties of the processes alloy were determined by the accumulative dislocations density, which stopped the cube texture progression, microstructure stabilizing the microstructure, regardless of the work hardening.

Tensile Behavior and Microstructure Evolution of an Extruded 6082 Aluminum Alloy Sheet at High Temperatures

The hot tensile behavior of an extruded 6082 alloy sheet at varying temperatures and strain rates was investigated by a Gleeble3500 thermal simulation testing machine. The optical microscope (OM), scanning electron microscope (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were applied to observe the microstructure evolution. It is found that the flow stress of the studied alloy declines with increasing deformation temperature. When deformed at high temperatures, the density of dislocation decreases obviously. In addition, precipitate coarsening occurs, resulting in a decrease in deformation resistance. The dimple number of the fracture samples increases with temperature and the size of the dimple becomes deeper, exhibiting an excellent plasticity. The 6082 sheet presents anisotropy of mechanical behavior at 300 °C, this can be attributed to the fibrous grain and the Brass component {011}<211>. The anisotropic behavior seems to be slighter with an increase in temperature. No obvious anisotropic behavior was found when tensiled at 400 °C. Because it is easier to activate the slip system at elevated temperatures, meanwhile, the recrystallization begins to occur at 400 °C.

Evolution of microstructure and texture in Al-containing CoCrNi medium entropy alloys during severe warm-rolling

Al, as an alloying element, can influence the properties of the single-phase equiatomic CoCrNi MEA. In this study, different alloys of different Al concentrations added to CoCrNi MEA (AlxCoCrNi) were prepared by warm rolling to understand the effect of Al. The alloys were warm-rolled at 400 °C up to an 85% thickness reduction, followed by isochronal annealing at 700–1100 °C. The microstructure after deformation reveals the development of deformation heterogeneities such as shear bands and deformation nano-twins. The evolution of the weak brass component is seen after deformation. Different phases, such as BCC and sigma, evolve upon annealing treatment at different temperatures. The higher Al-content MEA (Al9.09) shows comparatively finer recrystallized microstructure irrespective of the annealing temperatures. Also, weak recrystallization texture develops after annealing, and the deformation texture components lying on α-fiber are preserved. This indicates the absence of preferential nucleation and growth during annealing. The hardness in the as-cast, deformed, and annealed conditions increases with increasing Al content, indicating the influence of Al in the strengthening of the AlxCoCrNi MEAs.

Assessing environmental impact in brass component companies through life cycle assessment: a case study of brass crafts smes

Sampurna Kuningan is a small and medium enterprises (SMEs) specializing in creating various brass metal handicraft products. They need to improve their efficiency in producing brass door handles within their manufacturing process. The issues mainly revolve around two tasks - dipping and refining processes. At the finishing stage, the chemical solution left from brass cleaning is improperly treated and disposed of in the sewer, wasting resources. This study’s primary objective is to evaluate the eco-efficiency index (EEI) value and propose improvement strategies to reduce the environmental impact caused by their production activities. The eco-efficiency measurement involves comparing the financial performance represented by the net value and the environmental performance measured as eco-cost. The eco-cost is calculated using a life cycle assessment through the Sima-Pro software. The results of the calculations indicate an EEI value of 2.22. The production process is both economically affordable and sustainable. However, there is a relatively high environmental impact during the finishing process. Improvement scenarios for this process include implementing water treatment or substituting finishing chemicals. Using citric acid for a brass door handle yields a significant average reduction in eco-cost, reaching approximately 50%.

Comparison of a copper processed by asymmetric unidirectional rolling (AUR) and cross rolling (ACR): Strain distribution, microstructure, texture, and mechanical properties

In this work, the effect of strain path on the strain distribution, microstructural evolution, crystallographic texture, and mechanical behavior of electrolytic tough-pitch copper was investigated by simulation and experimental procedures. The asymmetric unidirectional and cross rolling processes with a thickness reduction of 90% were performed at room temperature. The asymmetric cross-rolling (ACR) gives much better through-thickness uniformity of shear strain distribution compared to the asymmetric unidirectional-rolling (AUR). The average equivalent strain of AUR and ACR after 90% rolling reduction was 3.99 ± 1.22 and 3.66 ± 0.26, respectively. Both AUR and ACR processes improved the particle distribution in the matrix. However, the particle distribution of the AUR sample was slightly more uniform compared to the ACR sample. The shape of primary grains in the AUR copper was straight while that in the ACR sample was zigzag. The average dislocation density of the AUR sheet was larger than that of the ACR sample (2.41 × 1016 m−2 vs. 2.31 × 1016 m−2). The major recrystallization mechanism in the AUR and ACR samples was discontinuous and continuous dynamic recrystallization, respectively. The main deformation textures (Copper, S, and Brass components, and α and β fibers) were weak in both samples due to the domination of recrystallization and shear textures in the cold-rolled copper. The recrystallization texture components in the upper region were stronger than in the lower region. The uniformity of the microhardness profile of the ACR sample was more than that of the AUR sample. The AUR sample had a larger strength and a smaller ductility compared to the ACR sample. The results showed that the strain path of asymmetric rolling was effective on the strain-hardening behavior of copper during the tensile test. The fractograph of the ACR sheet exhibited ductile dimples. However, the fractograph of the AUR sample revealed many ductile shear dimples and flat surfaces.

Metallurgical pathways of lead leaching from brass

Leaded (Pb) brass components used in water pipeworks are prone to lead leaching following soldering or brazing during installation. Synchrotron radiation X-ray imaging shows that in the initial state of potable-water grade brass samples, Pb exists mainly as isolated or linked-together particles from sub-micron to several microns large. On heating to the usual soldering temperature of ~200 °C, the Pb contents surface rapidly via diffusion pathways involving an interpenetrating Pb–brass structure with orientation relationship (11bar{1})α-brass//(220)Pb; [011]α-brass//[bar{1}13]Pb. On heating to the usual brazing temperature of 700 °C, the Pb particles melt and expand in volume, with the Pb content forced into the brass lattice preferentially along {101}α-brass planes, forming Pb phase of low sphericity or even large sheets. On immersion in water, the surfaced Pb particles are oxidized to form PbO needles along the normal direction of {bar{2}bar{2}2}PbO planes, which are then easily washed away to cause Pb leaching.

Effects of microstructure and texture on the deep drawability of C10200 copper sheets

Formability of copper sheet is generally affected by microstructure and crystallographic texture. In this study, the effects of two different microstructure and textures on the deep drawability of C10200 copper sheets were analyzed by the optical microscopy (OM), the scanning electron microscopy (SEM) and the electron back-scattered diffraction (EBSD) technique. The results show that the first rolling reduction rate before intermediate annealing decreased, and the strong {001}<100> (Cube) texture was formed after final annealing. When the second rolling reduction decreased, Cube texture was weak and final annealing textures dominated by {123}<634> (S), {112}<111> (Copper) and {110}<112> (Brass) components were obtained. The texture difference had a great influence on the deep drawing quality. Strong Cube texture was unfavorable for deep drawing because of the more heterogeneous strain distribution resulted from the remarkable planar anisotropy, while the coexistence of S, Copper, Brass, and {110}<001> (Goss) texture components was conducive to improving the average r-values, which was beneficial to the deep drawability.

Influence of intercritical annealing temperature on microstructure, microtexture, and tensile behavior of TRIP-assisted medium manganese steel

The present work investigates, the effect of intercritical annealing temperature on the microstructure, microtexture, tensile behavior, and mechanical stability of austenite in thermomechanically processed Fe-0.18C-4Al-7Mn (wt.%) medium manganese steel. The steel is subjected to thermomechanical processing (hot forging and hot rolling) followed by intercritical annealing at various temperatures (700, 750 and 800 °C) for 1 hour. The development of a complex microstructure with blocky and lath-type reverted austenite (RA), fine polygonal and blocky type intercritical ferrite (IF), coarse elongated ferrite (EF), and lath martensite (M) is revealed by the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. The steel annealed at 750 °C exhibits an excellent ultimate tensile strength (UTS) of 802 MPa and total elongation (TE) of 61% owing to its high RA content, high transformation-induced plasticity (TRIP) effect and low mechanical stability of RA. Further, to understand the dislocation phenomena during tensile deformation, the tensile samples are analyzed using TEM, which reveals dislocation interactions, dislocation tangles, and dislocation accumulations at the IF grain boundaries and martensite lath boundaries. The manifestation of the TRIP effect is elucidated by XRD and EBSD studies. In addition, to study the texture evolution and the role of texture components on the TRIP effect, the orientation distribution function is employed. The major texture component, i.e., Ms Brass {011} 〈211〉 indicates the TRIP effect resulting in the deformation-induced martensitic transformation under tensile deformation. Additionally, Ms Brass component shifts towards G/B (Goss/Brass) twin {011} 〈111〉 component by grain rotation to accommodate the deformation.

The effect of microstructural and texture evolutions during thermomechanical treatment on corrosion resistance of 310s austenitic stainless steel

In this study, the evolution of the microstructure and texture during thermomechanical treatment and its effect on corrosion properties of 310s austenitic stainless steel were investigated. This stainless steel was cryo-rolled at 50 and 90% thickness reductions, and then the 90% cryo-rolled sample was annealed at 750 °C for 5 and 30 min. SEM and optical microscope images were used to examine the microstructure of the samples. Fritoscopy test was also used to calculate the volume fraction of the martensite phase. Electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and cyclic potentiodynamic polarization tests were performed in the 3.5 wt.% NaCl solution to investigate the corrosion behavior of the studied steel. The results showed that the cryo-rolling process caused the reduction of grain size, texture strengthening and transformation of austenite to strain-induced αʹ-martensite phase. Decreasing grain size and increasing texture components containing dense planes are beneficial factors and the formation of the αʹ-martensite phase is a harmful factor for corrosion resistance. It was observed that annealing at 750 °C for 30 min caused the grain growth and texture weakening, while a favorable condition is developed in the annealed sample for 5 min. After 90% cryo-rolling and subsequent annealing at 750 °C for 5 min, the corrosion resistance was significantly improved compared to the as-received sample and reached 37 kΩ.cm2. Formation of the sub-micron microstructure along with the high volume fraction of Brass and Goss texture components were the main reasons for improving corrosion resistance at 750 °C–5 min.

Developing a new method to represent the low and high angle grain boundaries by using multi-scale modeling of crystal plasticity

The main goal of the research is an investigation on a multi-scale crystal plasticity of a finite element model for polycrystalline material by using a hierarchical computational framework and macro/micro structure analysis. Therefore, several systematic numerical studies on the evolution of the microstructure and texture of pure Aluminum during torsion have been performed to identify crystal misorientation. The framework is integrated into ABAQUS finite element package using Düsseldorf Advanced Materials Simulation Kit (DAMASK) software. Then a Python algorithm was developed to examine the high and low grain boundaries, and the results were compared to experimental data of electron back scattering diffraction (EBSD). The findings showed that the torsion texture of pure Aluminum is completely attributed to dislocation sliding, and it was predictable by crystal plasticity. It was also shown that the Brass component with (φ1,ϕ,φ2)=(35°,45°,0°) appeared in the deformed sample. As a result, it is demonstrated that the multi-scale crystal plasticity simulation can predict the effect of inhomogeneous strain on the deformed texture.

Effect of post-weld heat treatment on the microstructure and mechanical properties of SSFSW HVDC AlSiMgMnCu alloy

The high vacuum die casting (HVDC) AlSiMgMnCu alloy sheets were successfully welded by stationary shoulder friction stir welding (SSFSW) technique, and a post-weld heat treatment (PWHT) was also performed to enhance the mechanical properties of the joints. The microstructure and maximum texture intensity obviously change in different zones before and after the heat treatment. In the as-SSFSW joint, the microstructure in nugget zone (NZ) and thermal mechanically zone (TMAZ) possessed stronger texture of brass components than the heat affect zone (HAZ). After the T6 PWHT, the joints of the alloy showed continuous recrystallization. The texture type is still brass texture in NZ and TMAZ, while the texture intensity in the NZ and TMAZ significant increased. Some grains in NZ and TMAZ rotate 20° towards the <111>. The nano-precipitation β'', Q′ and θ′ phases formed in the Al matrix after the T6 PWHT. The yield strength, ultimate strength and elongation of PWHT joints are 252 MPa, 297 MPa and 4.1%, respectively. The joint welding coefficient of PWHT joint is 96.1%, which was ascribed to dislocation and precipitation strengthening.

Versatile DIY Route for Incorporation of a Wide Range of Electrode Materials into Rotating Ring Disk Electrodes.

Rotating ring disk electrodes (RRDEs) are a powerful and versatile tool for mechanistically investigating electrochemical reactions at electrode surfaces, particularly in the area of electroanalysis and catalysis. Despite their importance, only limited electrode materials (typically glassy carbon, platinum, and gold) and combinations thereof are available commercially. In this work, we present a method employing three-dimensional (3D) printing in conjunction with machined brass components to produce housing, which can accommodate any electrode material in, e.g., pressed powdered pellet, wafer, rod, foil, or vapor deposited onto a conductive substrate form. In this way, the range and usability of RRDEs is extended. This custom do-it-yourself (DIY) approach to fabricating RRDEs also enables RRDEs to be produced at a significant fraction of the cost of commercial RRDEs. To illustrate the versatility of our approach, coplanar boron-doped diamond (BDD) RRDEs are fabricated for the first time using the approach described. Experimental collection efficiencies for the redox couple FcTMA+/FcTMA2+ are found to be very close to those predicted theoretically. BDD electrodes serve as an ideal electrocatalyst support due to their low background currents, wide solvent potential window in aqueous solution, and chemical and electrochemical stability in acid and alkali solutions. The BDD RRDE configuration is employed to investigate the importance of surface-incorporated nondiamond carbon in BDD on hydrogen peroxide generation via the oxygen reduction reaction in acid solutions.

Microstructural Evolution and Mechanical Properties of Pure Aluminum upon Multi-Pass Caliber Rolling.

The paper presents the microstructure and mechanical property of pure aluminum (Al) fabricated by multi-pass caliber rolling at room temperature. The finite element modeling (FEM) simulation was performed to explore the changes in rolling force, effective stress and strain, and temperature under various rolling passes. As the number of rolling passes increased, the overall temperature, effective stress, and strain gradually increased, while the maximum rolling force decreased. In addition, due to the dynamic recrystallization (DRX), the average grain size reduced from 1 mm to 14 µm with the increase in rolling passes. The dislocation density increased and it gradually evolved into the high-angle grain boundaries (HAGBs). Moreover, the initial cubic texture rotated to the brass component and finally changed to a mixture of Cube and Brass types. The highest tensile yield strength (TYS), ultimate tensile strength (UTS) and elongation (El.) of caliber rolled pure Al (116 MPa, 135 MPa, and 17%, respectively) can be achieved after 13 rolling passes, which mainly attributed to grain refinement.

Microstructure and texture of severely warm-rolled and annealed coarse-grained CoCrNi medium entropy alloy (MEA): A perspective on the initial grain size effect

Microstructure and texture formations were investigated in a coarse-grained starting material (average grain size ~100 µm) of equiatomic CoCrNi MEA after severe warm-rolling and annealing. The results were compared with a fine-grained starting material (FGSM with average grain size ~7 µm) to highlight the effect of starting grain size. Progressive microstructural evolution accompanied by deformation bands, shear bands, and nano-twins formation resulted in an ultrafine microstructure in the heavily warm-rolled CGSM. The hardness of CGSM after 90% warm-rolling was similar to FGSM, indicating a rather comparable ultrafine microstructure. The deformation texture of the CGSM was rather similar to the FGSM featured by a weak brass component. Remarkably, the annealed grain sizes of the CGSM and FGSM series of specimens were rather similar. These observations amply corroborated with comparable deformation microstructure in the two materials. Both CGSM and FGSM showed weak recrystallization texture featured by the retention of deformation texture components. The results indicated rather limited effect of the starting grain size on microstructure and texture formation in warm-rolled and annealed CoCrNi MEA. Further, a remarkable strength-ductility balance could be obtained in annealed CGSM due to ultrafine microstructure and solid solution strengthening.

Microstructure and texture development in CoCrNi medium entropy alloy processed by severe warm cross-rolling and annealing

The effect of cross-rolling on microstructure and texture evolution in equiatomic CoCrNi medium entropy alloy (MEA) was investigated in the present work. For this purpose, the MEA was warm-rolled to 90% reduction in thickness at 400 °C by unidirectional and different cross-rolling routes. The heavily deformed specimens were further annealed at temperatures varying from 700 °C to 1200 °C. The development of fine-scale microstructures and profuse shear band formation was confirmed in all the processed materials. Compared to unidirectional processed material, the different cross-rolled materials showed greater propensity for forming intersecting shear bands. Higher hardness in the different cross-rolled materials was consistent with finer microstructure and abundant shear bands. Unidirectional processed material showed weak brass ({110}<112>) component, whereas the different cross-rolled material showed rotated brass components. Upon annealing, the different cross-rolled materials showed smaller grain sizes than the unidirectional processed material due to more abundant potential nucleation sites. The recrystallization texture of the different processed materials showed retention of the deformation texture components. High fractions of random components indicated weak recrystallization texture, contributed by the absence of preferential nucleation and growth and profuse annealing twin formation.

An investigation of cryogenic-aging process attemptted to alleviate mechanical anisotropy of 7055 thick plate

Considering the application of cryogenic treatment in aerospace manufacturing field, the hot rolled 7055 Al–Zn–Mg–Cu alloy thick plate was selected in order to solve its mechanical anisotropy. Several cryogenic-aging processes were applied by introducing deep cryogenic treatment, pre-deformation and natural aging as pre-treatments and two-stage artificial aging as final treatment. An optimized artificial aging parameter in this paper is 110 °C/6 h + 130 °C/16 h, for a best preformance (Rm-max = 668 Mpa, Rp0.2-max = 635 Mpa, A25mm-max = 8.52%) in transverse direction. Nearly all the samples pre-treated by various cryogenic processes obtain stable plastic deformation capacity. Generally, there exist geometric recrystallization, continuous recrystallizaion and discontinuous recrystallization, to some extent in different period of cryogenic-aging process. The final morphology is the result of a mutual compromise between pinning effect originated from cryogenic or natural aging precipitates and recrystallization driving force originating from the energy stored in cryogenic or pre-tensile deformed microstructure. For the thick plate of hot-rolled AA7055, the pair of original rolling Brass components can be enhanced by cryogenic treatment or compressive deformation along transverse direction. But the final texture and the morphology of Σ3n GBs are affected mainly in artificial stage due to various abilities of recovery and discontinuous recrystallization in different directions. Tensile plastic deformation and cycled cryogenic treatment can destroy the Brass components, together with continuous straight geometrically necessary boundaries, more effectively. Since precipitation is probablely accelerated through pre-treatments, a modification of artificial aging time has promising prospect to achieve more excellent mechanical performance.