Goss Component Research Articles

On the Relationship between Thermomechanical Processing Parameters and Recrystallization Texture in AA1100 Aluminum Alloy

In this study, 48 hot-rolling processing conditions were designed to investigate the influences of thermomechanical processing parameters on the recrystallization behavior and texture development. The hot-rolling experiments were conducted using the thermomechanical simulator Gleeble 3800 at temperatures of 275, 300, and 350 °C with strain rates of 5 and 90 s−1 up to 60 and 85% reduction. The microstructure and texture analysis were measured by using the EBSD technique on a large area. Experimental results show that the Cube component maintains a volume fraction between 10% and 20%, below the 40% recrystallization fraction, but the volume fraction of Cube significantly increases between 20% and 50% above the 40% recrystallization fraction. However, the fractions of Rotated Cube (RC) and Goss components remain below 10%.

Evolution of recrystallization texture in medium to low stacking fault energy alloys: Experiments and simulations

The present work aims to investigate the evolution of static recrystallization microstructure and texture in medium to low stacking fault energy (SFE) alloys. In these categories of materials, the process of recrystallization becomes complex because of the presence of extensive deformation heterogeneity. Ni-xCo (40 and 60wt.% Co) alloy has been chosen for this purpose, where Ni-40Co belongs to medium SFE, and Ni-60Co belongs to low SFE regimes. The effect of solid solution strengthening and deformed microstructural features on the mechanism of recrystallization are explored. Both the alloys were subjected to 50% cold-rolling reduction followed by isothermal annealing at 600°C. Recrystallization texture of Ni-40Co shows a non-uniform α-fiber having a peak intensity at the Goss component, whereas Ni-60Co shows uniform α-fiber texture. Both the alloys also show rotated cube (Rt C) and rotated Cu (Rt Cu) components after recrystallization. Apart from that Ni-60Co exhibits brass recrystallization (BR) texture component. The differences in the recrystallization texture in both the Ni-Co alloys are attributed to the role of different heterogeneous deformation features in the microstructure and transition from Cu-type to Bs-type as-deformed texture. The recrystallization microstructure is dominated by the formation of substantial annealing twin (Σ3) boundaries, which also produces many new orientations; thereby weaken the recrystallization texture. These experimental findings and the proposed mechanism were used as input to simulate the recrystallization microstructure and texture in the alloy using the parallelized cellular automata (CA) technique. Parallelized CA model has successfully predicted the evolution of recrystallization texture and microstructure through simulation except parallel annealing twin feature.

Directed laser deposition of super duplex stainless steel: Microstructure, texture evolution, and mechanical properties

Microstructure and texture evolution of directed-laser deposited super-duplex stainless-steel, in the as-received block, were characterized using light and electron microscopies and electron backscattered diffraction. Mechanical properties in different directions were studied. Local FCC-depleted and FCC-rich zones and extensive precipitation of oxides were detected at the matrix wherein the different types of reformed austenite were surrounded by the elongated coarse ferrite. A vertical gradient of austenite content, caused by overall change in cooling rate, generated a waning hardness distribution along the building direction. The texture of austenite across the different deposition layers was not as intense as that of the ferrite. A dominant ⟨001⟩ ⫽ND fibre, embedding strong Cube {001}⟨100⟩, was calculated for ferrite on the layer away from the bottom while the Goss {011}⟨100⟩ appeared in the layer near the building substrate due to the considerable epitaxially developed grains. The less intensified multi-component texture of austenite at the layer near the substrate changed to ⟨011⟩ ⫽ND fibre adorned by Rotated-Goss and Goss components at the upper layers where an incomplete fibre {001}⟨uvw⟩ with a major Rotated-Cube was also partially inherited from the parent phase. The inter-phase boundaries obeying Kurdjumov-Sachs orientation relationship were predominantly formed at all layers. A slight increase of Σ3 coincidence site lattice interfaces was observed in austenite across the build direction. The possible mechanical anisotropy was depressed due to complex and multi-component transformation texture of the austenite. The material showed brittleness corresponding to significantly high tensile strength and low impact toughness.

Microstructure and crystallographic texture of martensitic stainless steels after cold rolling and subsequent recrystallization

Martensitic transformation occurs after the final conformation in the quenching process of martensitic stainless steels. Ferrite grains and Cr-rich carbides are observed in the microstructure during the hot rolling, cold rolling and annealing industrial processes. In this context, this study investigated the microstructures and textures of AISI 410, AISI 420 and EN 1.4116 stainless steels with different carbide fractions, initial grain sizes and initial textures after 50% cold rolling reduction and recrystallization. The experimental results showed that the stored energy after cold rolling and grain growth during the annealing were mainly influenced by the (Cr,Fe) 23 C 6 carbide fraction, which was identified as Cr 15.58 Fe 7.42 C 6 carbide type. Reducing initial grain size caused a larger grain boundary constraints, weakening the {110}〈001〉 Goss component in recrystallized texture. The initial texture and pinning effect of (Cr,Fe) 23 C 6 carbides favored α-fiber retention and texture gradient after recrystallization in AISI 410 steel. The recrystallized microstructures of AISI 420 and EN 1.4116 steels were heterogeneous owing to the (Cr,Fe) 23 C 6 carbide bands in the as-received condition. In addition, the selective particle drag caused the γ-fiber development with a shift toward (334)[4 8 ¯ 3] component in AISI 420 and EN 1.4116 steels. • Transition between deformation heterogeneities to larger grain boundary constraints with the reduction of initial grain size was observed after cold rolling. • The initial texture and the pinning effect of (Cr,Fe) 23 C 6 carbides favored α-fiber retention and texture gradient after recrystallization in AISI 410 steel. • The selective particle drag caused the γ-fiber development with a shift toward (334)[4 8 ¯ 3] component in AISI 420 and EN 1.4116 steels.

Effect of heat treatments on the mechanical and microstructural behavior of a hypoeutectic Al alloy obtained by laser powder bed fusion

Large gains in strength and ductility are of little significance if the material’s anisotropy is high. Therefore, improving the mechanical properties and reducing the anisotropy of Al alloys obtained by additive manufacturing is a topic of growing interest. This manuscript examines the effect of distinct heat treatments on the mechanical, anisotropic, and microstructural behavior of a hypoeutectic, almost eutectic, AlSi11Cu alloy obtained by laser powder bed fusion (L-PBF). The microstructural characterization revealed an Al matrix surrounded by a Si-rich network, forming a coral-like pattern with a heterogeneous combination of columnar and equiaxed grains. The texture indicated that the columnar grains were preferentially oriented towards the building direction with strong Cube and Goss components. Different strength-ductility ratios were obtained following the annealing and solution heat treatments at different temperatures (200 °C–550 °C) with a holding time of 1 h. In terms of grain size and dislocation density, no significant changes were found in the microstructure, suggesting that grain size and dislocation strengthening mechanisms are not highly affected by the heat treatments. In addition, the Si-enriched network remained interconnected until 300 °C. At higher temperatures, this interconnection was lost, giving rise to large Si particles depleting the Si content in solid solution in the Al matrix. Digital image correlation maps revealed that deformation fields were more homogeneous when the cellular structure disappeared. The visco-plastic self-consistent model showed that when applying the load at 30° in the building direction (BD), the largest tensile strength was generated, whereas the lowest strength was obtained when the load was parallel to the BD. Heat treatments for 1 h holding time were found to be efficient in reducing the Lankford coefficients dispersion, suggesting improvements in formability and reducing the alloy’s planar anisotropy. These results revealed that annealing up to 400 °C or higher temperatures followed by water quenching leads to good strength and ductility ratios while reducing anisotropy.

Secondary Recrystallization Texture and Magnetostriction in Fe-Ga Alloy Ultra-Thin Sheet

The 0.15 mm thick Fe-Ga alloy ultra-thin thin sheets with high magnetostriction were successfully produced by the conventional processing route including hot rolling and two-stage cold rolling with intermediate annealing and primary and secondary recrystallization annealing. The evolution of microstructure, texture, and inhibitor was briefly investigated. The primary recrystallization texture is characterized by strong <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\gamma $ </tex-math></inline-formula> fiber with the peak at {111} <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\langle 112\rangle $ </tex-math></inline-formula> component and weak Goss component through sheet thickness. The dispersedly distributed nano-precipitates provide a sufficient pinning effect on the primarily recrystallized grains and induce abnormal grain growth of Goss grains. Well-developed secondary recrystallized Goss grains with centimeter size and maximum magnetostriction (3/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2\lambda \text{s}$ </tex-math></inline-formula> ) of 229 ppm were achieved in Fe-Ga alloy ultra-thin sheet.

Ultrafast Heating Heat Treatment Effect on the Microstructure and Properties of Steels

The adoption of the ultrafast heating (UFH) process has gained much attention in the last few years, as the green energy and minimization of CO2 emissions are the main aspects of contemporary metal science and thermal treatment. The effect of ultrafast heating (UFH) treatment on carbon steels, non-oriented grain (NGO) electrical steels, and ferriticor austenitic stainless steels is reported in this review. The study highlights the effect of ultrarapid annealing on microstructure and textural evolution in relation to microstructural constituents, recrystallization temperatures, and its effect on mechanical properties. A strong influence of the UFH process was reported on grain size, promoting a refinement in terms of both prior austenite and ferrite grain size. Such an effect is more evident in medium–low carbon and NGO steels than that in ferritic/austenitic stainless steels. A comparison between conventional and ultrafast annealing on stainless steels shows a slight effect on the microstructure. On the other hand, an evident increase in uniform elongation was reported due to UFH. Textural evolution analysis shows the effect of UFH on the occurrence of the Goss component (which promotes magnetic properties), and the opposite with the recrystallization g-fiber. The recovery step during annealing plays an important role in determining textural features; the areas of higher energy content are the most suitable for the nucleation of the Goss component. As expected, the slow annealing process promoted equiaxed grains, whereas rapid heating promoted microstructures with elongated grains as a result of the cold deformation.

Different formation mechanisms of {210} orientation in η fiber texture of ultra-thin grain-oriented silicon steel using quasi-in-situ analysis method

Using high-permeability grain-oriented silicon steel as starting material, an ultra-thin grain-oriented silicon steel was prepared by the primary recrystallization method, which was mainly composed of strong η fiber (<100>//RD) texture including major Goss ({110}<001>) component, a certain amount of {210}<001> component and a few Cube ({100}<001>) grains. In this study, the formation of η fiber texture, especially the {210}<001> component, was analyzed by a quasi-in-situ analysis method. The results show that the {210}<001> texture exists in two forms. The first type, characterized by some {210}<001> grains distributed in Goss grain colony, is common in the product. The texture originates from exact Goss initial grain, and the {210}<001> nuclei are mainly observed in shear bands of {111}<112> rolling texture. The {210}<001> nuclei are mainly distributed in the surface and subsurface layers and are formed by roller friction. The second type is a sharp {210}<001> texture together with a few scattered Cube grains. After rolling, large {210}<001> initial grain rotates toward {112}<241> deformation texture, which is swallowed by transition bands composed of many {210}<001> nuclei and a few Cube nuclei during annealing. This is because the transition bands act as principal sites for nucleation. A few Cube grain clusters originating from {210}<001> initial island grains are observed, and the Cube nuclei are formed by a strong rotation effect of initial grain boundaries. Due to the high-angle boundaries with Goss grains, the {210}<001> grains grow abnormally at higher temperature, and the magnetic properties deteriorate because of large deviation angle of <001> axis from the rolling direction.

Microstructure and crystallographic texture of Cu-Zn alloys subjected to ECAP and flat rolling

This paper presents the results of the microstructure and crystallographic texture investigations of the Cu-Zn alloys system with different stacking fault energies (SFE) subjected to severe plastic deformation (SPD) by equal channel angular pressing (ECAP) and subsequent flat rolling. It is shown that ECAP leads to the formation of an ultrafine-grained (UFG) structure. Further flat rolling is accompanied by a decrease in the size of structural elements and the formation of nanoscale twins, which are more likely to be detected in an alloy with a lower SFE. As the deformation degree increases, the main crystallographic textures components of the investigated alloys become Brass and Goss components.

Influence of out-of-plane stretch forming induced different strain paths on micro-texture evolution, slip system activity and Taylor factor distribution in Al–Li alloy

A detailed investigation on the microstructure and micro-texture evolution in Al–Li alloy has been carried out following deformation at various strain paths. The stretch forming tests have been conducted to achieve three distinct strain paths, viz. close to uniaxial, plane strain and equi-biaxial. A correlation has been established between the microstructural and micro-textural developments with the various strain paths. The development of Brass {110}<112> and Cube {001}<100> components during uniaxial deformation and evolution of Goss component {110}<001> with development of <011>//ND fiber during equi-biaxial deformation have been observed as stable orientations. Meanwhile, a marginal strengthening of R {214}<112> and S component {123}<634> is noticed during plane strain deformation. The deformation micro-texture and associated active number of slip systems under different deformation modes are simulated using visco-plastic self-consistent (VPSC) polycrystalline model. During uniaxial deformation, the availability of the least number of active slip systems leads to the development of a relatively stronger micro-texture. Moreover, a detailed insight into the Taylor factor has been performed to elucidate its distribution based on the micro-textural developments along the three deformation paths. The higher fraction of grains in Taylor factor range M ∼ 2–3 during uniaxial and plane strain deformation is associated with the presence of Cube component {001}<100>. On the contrary, the higher fraction of grains in Taylor factor range M ∼ 3–4 during equi-biaxial deformation is related to the strengthening of <011>//ND fiber. The fewer number of grains in Taylor factor range M ∼ 4–5, as observed during plane strain deformation, is attributed to the evolution of Brass texture {110}<112>.

Synthesis and Characterization of a Ti–Zr‐Based Alloy with Ultralow Young's Modulus and Excellent Biocompatibility

Recently, metastable β‐type Ti alloys have attracted attention as promising materials for medical implants due to low Young's modulus and superior biocompatibility. The former is dependent on texture developed during the thermomechanical process. Herein, new Ti–Zr–Nb–Sn–Mo alloys with ultralow Young's modulus and excellent biocompatibility are developed as promising materials for medical implants. The effect of Mo on the microstructure and mechanical properties of the Ti–18Zr–5Nb–3Sn system is investigated. X‐ray diffraction (XRD) and scanning electron microscope (SEM) results reveal that Mo acts as a β‐phase stabilizer. Moreover, mechanical behavior and recrystallization texture show strong composition dependence; the 2.5Mo alloy shows the lowest Young's modulus of 40 GPa. This is due to the formation of a recrystallization texture with strong Goss component of &lt;001&gt;. Corrosion behavior of the 2.5Mo alloy in the cell culture medium is similar to that of the commercially pure titanium (cp‐Ti), suggesting excellent corrosion resistance in the biological environment. Both murine fibroblasts and osteoblastic cells show good growth on the 2.5Mo alloy as the same level of that on the cp‐Ti. Implantation into rat subcutaneous tissue confirms no significant difference in the tissue reaction between the 2.5Mo alloy and the cp‐Ti.

Thermal stability of microstructure, mechanical properties, formability parameters and crystallographic texture in an Al-7075 alloy processed by accumulative roll bonding

Accumulative roll bonding (ARB) is a severe plastic deformation (SPD) technique that has been extensively used in a wide range of metals to improve their mechanical properties. In particular, ARB processed materials display an increase in both yield and ultimate tensile strength, since the SPD processing induces a remarkable grain refinement. In precipitation-hardened alloys, such as aluminum 7075, this leads to a synergistic effect which further enhances strength. Although the reported results are promising for high-strength applications, thermal stability of the microstructure after processing remains an open question. In this paper, we present an investigation of the thermal stability of the texture, microstructure, and mechanical properties of Al-7075 samples processed by ARB to an equivalent Von Mises strain of 240%. After processing, yield and tensile strength displayed improvements of 30% and 20% respectively over the T6 condition. Crystallographic texture was found to depart from the rotated cube component to Dillamore/Taylor and Goss components. Several annealing heat treatments ranging from 373 to 673 K (100–400 °C) were carried out and it was found that the improved mechanical properties are stable up to 423 K (150 °C). The texture was found to slowly revert to a rotated cube with increasing temperature. The results are discussed in terms of the combination of strength and formability as calculated by the Lankford parameter using the visco-plastic self-consistent code (VPSC).

The Occurrence of a Peripheral Coarse Grain Zone (PCGZ) in Extruded Bars of AA 7108

Industrial-scale extruded profiles of AA 7108 with a rectangular section (25.60 mm x 15.95 mm) were used in this investigation. Some complementary microstructural analysis techniques, such as polarized light microscopy, EBSD (Electron Backscatter Diffraction) and X-ray diffraction were used to characterize the microstructure, focusing on the PCG zone. It was observed that the extruded profiles presented a totally recrystallized microstructure and a 300 μm layer of peripheral coarse grains. Additionally, the results showed that the PCGZ predominant grain orientation {311} &lt;110&gt; differs from the texture below the PCGZ (Goss and Cube components).

Effect of Cold Rolling Path on the Deformation Textures Of C10300 Copper

Commercially free, C10300 Copper was submitted to cold rolling to 80% thickness reduction using three different rolling schedules. Rolling was conducted in 5, 8 and 11 rolling passes. Samples were then submitted to EBSD analysis at the surface and X-Ray Diffraction at the surface and mid-thickness to evaluate the deformation texture. EBSD analysis showed an increase in the intensity of the Copper component at the surface as the number of rolling passes decreased, and a very strong Goss component in all samples analyzed. X-ray diffraction analysis confirmed the strong copper component, but the Goss texture was much weaker when analyzed by X-ray diffraction, ultimately being nearly inexistent at mid thickness. The Brass component was very weak in EBSD analyses, but was found with higher intensity when texture was calculated using x-ray diffraction. The appearance of Goss component in surface grains can be explained by friction and shearing conditions in the roll-metal contact.

Achieving an exceptional ductility at room temperature in a low SFE copper alloy fabricated by severe plastic deformation

Abstract Low stacking fault energy alloys often exhibit low ductility. However, sometimes these alloys show unusual mechanical behavior following specific processing parameters. In this study, a low stacking fault energy α+β brass was processed by equal channel angular pressing (ECAP) at 350 °C in ‘route C’ through three passes. Room temperature tensile testing showed that ductility, surprisingly, reached ~80%, whilst good tensile strength was maintained. Investigation of alloy microstructure revealed a combination of deformation mechanisms, including slip and twinning, accompanied by grain boundary serration and grain fragmentation. It is suggested that these deformation modes triggered these unexpected mechanical properties in this intrinsically brittle alloy. The required energy for discontinuous recrystallization was supplied after only one pass in the α phase, and three passes in the β phase, which then prompted good ductility. In order to study texture evolution, the macro-texture was measured. A high fraction of recrystallized grains and change in strain path fostered the development of Goss, Rotated Goss and Rotated Cube components in the α phase. While in the β phase {011} and Goss components were dominant. Despite the high Schmid factor, Hall-Petch effects and work hardening led to increase of strength and hardness after the final pass.

Texture development in 304LN austenitic stainless steel during post-hot-axisymmetric compression

In the present work, 304LN austenitic stainless steel has been considered for the texture evolution study after the hot-deformation process. The axi-symmetric compression tests, with post-deformation isothermal holding at the same temperature, were performed at 900°C, 1000°C and 1100°C with a strain rate of 0.1 s−1. Texture evolution during the post-hot-deformation was studied through electron back scattered diffraction. Effect of temperature and holding time on texture evolution were studied. At low deformation temperature and lesser holding time 〈100〉 and 〈110〉 fibre textures were observed. At high deformation temperature and/or high holding time the texture becomes random. Texture intensity along α fibre, for all the temperatures, is chaotic whereas along β and τ fibres it is uniform at low temperature and becomes chaotic with the increase in deformation temperature. Goss component was found to be a major texture component with significant amount of ND and RD rotated cube components.

Microstructure and Properties of Inconel 625 Fabricated Using Two Types of Laser Metal Deposition Methods.

The effect of using two different deposition systems on the microstructure and mechanical properties was studied in this paper. For this purpose, laser-engineered net shaping (LENS) and high-power CO2 laser deposition processes were applied to fabricate Inconel 625 samples. The microstructure of the Inconel 625 produced by both additive techniques was characterized using light microscopy (LM), scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). The mechanical properties were characterized by tensile tests and microhardness measurements. High-power laser application resulted in a strong <100> build texture, while, at low powers, the {011} <100> Goss component increased. Both types of deposited materials showed dendritic microstructures with Ti-, Mo-, and Nb-rich zones at the cell boundaries, where numerous precipitates (Nb2C, NbC, titanium carbides, Nb3Ni, and NbNiCr) were also observed. It was also noted that both variants were characterized by the same slope with a proportional length, but the Inconel 625 fabricated via LENS showed a higher average yield strength (YS; 524 MPa vs. 472 MPa) and ultimate tensile strength (UTS; 944 MPa vs. 868 MPa) and lower elongation (35% vs. 42%) than samples obtained with the high-power CO2 laser deposition process.

Effect of Nb content on primary recrystallization microstructure, texture and magnetic properties of grain-oriented silicon steel manufactured by low-temperature slab reheating

The influence of Nb content on the primary recrystallization microstructure, crystallographic texture and magnetic properties of grain-oriented silicon steel manufactured by low-temperature slab reheating were studied. The results show that the effect of grain refining was enhanced with the increase of Nb content. With the increase of Nb content, the total contents of texture {111}〈112〉 and {114}〈481〉 in primary recrystallization which are beneficial to the secondary recrystallization increased, but the contents of deviated Goss component and adverse textures with abnormal growth ability in primary recrystallization also increased, which led to the deterioration of magnetic properties. By adding 0.005% Nb, the average size of the primary grain reduced to 23 μm, the content of {110}〈112〉 increased slightly and the least deviated Goss nuclei were obtained, therefore the final product had the sharpest {110}〈001〉 texture of secondary recrystallization and the best magnetic properties with B800 = 1.873 T , P1.7/50 = 1.21 W/kg.

The Microstructure, Texture and Mechanical Properties of Friction Stir Welded Aluminum Alloy

The microstructure and texture of 7075-T6 FSW weld with optimal parameters are investigated using optical microscopy, electron back scatter diffraction and neutron diffraction. The mechanical properties are characterized through microhardness, nanoindentation and ultrasonic tests. The friction stir welding is performed at a nominal rotational speed of 1400 rpm and a traverse speed of 60 mm/min. The nugget zone contained fine, equiaxed and fully recrystallized grains. The texture of the base material mainly consisted of Cube and rotated Goss components. However, in the nugget zone, the dominant texture components were B and $${\bar {\text{B}}}$$ among common shear orientations. Elastic modulus was measured by ultrasonic and nanoindentation methods. The ultrasonic method being nondestructive, easy, inexpensive and fast. It is found that a little increase of Young modulus is observed in nugget zone compared to base metal.

Comparison of Precipitates and Texture Evolution in Nb-Bearing Grain-Oriented Silicon Steel Produced by Conventional Processing and Novel Twin-Roll Casting

The Nb-bearing grain-oriented silicon steel sheets were produced by conventional route and novel twin-roll casting route, respectively. The microstructure, texture and precipitate evolution were comparatively investigated by using electron backscattered diffraction (EBSD) and transmission electron microscope (TEM). The findings revealed that the precipitation behavior and the texture evolution were totally different between the two processing routes. In the conventional route, a great number of nanoscale niobium nitride particles (NbN), which acted as mainly grain growth inhibitors were precipitated during hot rolling, while in the twin-roll casting route, due to the rapid solidification, the precipitation of NbN were suppressed and a new type Nb-bearing precipitate enriched with sulfur element was observed in the as-cast strip. Besides, the primary recrystallized texture of conventional specimens was characterized by strong γ-fiber with a peak at {111} &lt;110&gt;, together with very few Goss components. While in the case of twin-roll casting specimens, the strongest primary recrystallized texture was {111} &lt;112&gt; texture and the area fraction of Goss component was much higher than that of conventional specimens. After final high temperature annealing, complete secondary recrystallization was obtained in twin-roll casting specimens and the magnetic induction of B8 was 0.1 T higher than that of conventional specimens.