Stress Relief Annealing Research Articles

Low-Cost Preparation of Wafer-Scale Au(111) Single Crystals for the Epitaxy of Two-Dimensional Layered Materials.

Single-crystal Au(111), renowned for its chemically inert surface, long-range "herringbone" reconstruction, and high electrical conductivity, has long served as an exemplary template in diverse fields, e.g., crystal epitaxy, electronics, and electrocatalysis. However, commercial Au(111) products are high-priced and limited to centimeter sizes, largely restricting their broad applications. Herein, a low-cost, high-reproducible method is developed to produce 4 in. Au(111) single crystals from commercial Au foils, via an abnormal grain growth process. This methodology involves the initial preparation of a (100)-textured Au polycrystalline foil, followed by the evolution and continuous expansion of an Au(111) abnormal grain through one-site stress loading and stress-relief annealing in an Ar/H2 atmosphere. Theoretical simulations indicate that stress/strain and high-temperature treatments in the H2 atmosphere induce an intermediate disordered state, facilitating the evolution from polycrystalline Au(100) foil to single-crystal Au(111) foil. Furthermore, the resulting Au(111) foils have been utilized as model substrates for the oriented growth of two-dimensional transition metal dichalcogenides and their heterostructures with graphene. This work hereby puts forward an effective approach for large-scale, cost-effective production of metal single crystals, potentially revolutionizing their applications across various fields, from materials sciences to electronics and catalysis.

Stress relief treatment of aluminum/magnesium laminates fabricated by roll bonding technique.

Roll bonding of aluminum/magnesium laminates combines the good corrosion resistance of aluminum alloys with the beneficial mechanical properties of magnesium alloys. We studied the microstructure of aluminum Al-1051/AZ31 magnesium laminates fabricated by the roll-bonding process. The fabricated laminates were investigated in the as-fabricated condition and after subsequent stress relief annealing treatment at temperatures ranging from 200°C to 400°C. The investigation aims to determine the optimal temperature to decrease the residual stress of the severely deformed microstructure of the roll-bonded Al/Mg laminates. Internal residual stress can limit the application of such laminates. Such a thermal treatment enhances the interdiffusion of Al and Mg at the Al/Mg interface resulting in the formation of intermetallic phases. Intermetallic compounds are undesirable due to their brittleness and impact on the overall laminate structure and integrity. Detailed microstructure characterization of the intermetallic compounds and internal residual stress by means of recrystallization degree revealed that stress-relief treatment at 200°C/1h is sufficient to reduce internal residual stress and ensure adequate interdiffusion at Al/Mg interface to minimize the formation of brittle intermetallic compounds in the diffusion zone.

PROPERTIES OF JOINTS WELDED USING THE MAG METHOD S355J2+N STEEL AFTER PEENING PROCESS

The aim of the research was to determine the impact of peening of each weld on the properties of a butt joint made of S355J2+N steel welded using a ceramic washer. The welding process was carried out using the MAG method on a robotic station. The analysis was based on a comparison of three butt joints: after welded, with peening of each bead and with post weld heat treatment – stress relief annealing. High frequency peening (90Hz) of each bead made was intended to reduce stress in the weld joint by introducing compressive stress into it. A Weld Line 10 pneumatic hammer was used. Tests such as visual, penetration, radiographic and destructive tests (macroscopic, transverse tensile test, transverse bending test, impact strength test, hardness) are conducted on the test samples prepared in the MAG process. The test results are compared to the acceptance values from the ISO standard. Additionally, stress measurements were made using the Barkhausen effect based on the research procedure of the technology supplier. The research performed showed that use of high – frequency peening after each bead did not affect the negative results of all the required tests during the qualification of the welding technology of S355J2+N steel compared to the test plates (after welded and after post weld heat treatment – stress relief annealing).

Stress-relief annealing friendly Fe-based metallic glass-reinforced Al-Si-Mg-Zr alloy fabricated by laser powder bed fusion

ABSTRACT To enhance the thermal stability of L-PBF Al-Si-Mg alloy, Fe-based metallic glass powder was mixed with Al-Si-Mg-Zr powder to fabricate a novel alloy via L-PBF. The study systematically investigated the effects of process parameters on processability and the impact of stress-relief annealing (300 ∘ C–2h) on the microstructure and mechanical properties. Results showed that metallic glass addition improved surface quality. Plastic deformation was analysed using finite element and molecular dynamics methods. The as-built alloy had a cellular substructure with Al 3 Zr, Si, AlFeMgSi, and AlFeSi phases. Si nanoparticles and stacking faults were observed in α-Al cells. The as-built samples had yield strength (YS) of 249±4 MPa, ultimate tensile strength (UTS) of 434±6 MPa, and 6.3±0.3% elongation. Post-annealing, the alloy retained high strength and plasticity with YS of 255±3 MPa, UTS of 449±15 MPa, and 7.2±0.3% elongation, outperforming similar L-PBF Al-Si and Al-Si-Mg alloys.

Influence of Heat Treatment on Microstructure and Mechanical Properties of Laser Cladding Coatings

This study investigates the influence of various heat treatment processes on the microstructure and properties of laser cladding Fe314 coatings. The microstructure, phases, and impact fracture morphology of the cladding layer were observed using X-ray diffraction and scanning electron microscopy, among other methods. The hardness and impact performance of the cladding layer were also tested. The results indicated that there was compositional segregation and non-equilibrium microstructure in the untreated cladding layer, with an average microhardness of 368.67 HV and an impact toughness of 27 J, exhibiting quasi-cleavage fracture. The stress-relief annealing treatment resulted in a uniform distribution of M23C6 carbides inside the cladding layer. The pinning effect generated by M23C6 reduced the microhardness by 16.26% and increased the impact toughness to 54 J. The impact fracture surface exhibited ductile fracture. After secondary normalizing and annealing, the microstructure of the cladding layer transformed into a fine single-phase austenite structure, and fine M7C3 carbides precipitated at the grain boundaries. Under the effects of fine grain strengthening and dispersion strengthening, the microhardness of the cladding layer decreased by 38.14%, and the average impact absorbed energy of the specimen was 64 J, showing complete ductile fracture.

Creating heterostructures via laser powder bed fusion using titanium and stainless steel mixtures

Creating heterostructures via laser powder bed fusion using titanium and stainless steel mixtures

Impact of multi-scale microstructural heterogeneities on the mechanical behavior of additively manufactured and post-processed Nb-based C103 alloy

Impact of multi-scale microstructural heterogeneities on the mechanical behavior of additively manufactured and post-processed Nb-based C103 alloy

Influence of Partial Er Substitution for Sc on the Microstructure, Mechanical Properties and Corrosion Resistance of Short-Processed Al-4.7Mg-0.6Mn-0.3Zr-0.3Sc Sheets

Standard AA5083 (ZSE000), AA5083 modified with 0.3 wt.% Zr and 0.3wt.% Sc (ZSE330) and AA5083 modified with 0.3 wt.% Zr, 0.2wt.% Sc and 0.1wt.%Er(ZSE321) sheets were fabricated through a short process (including a simulated twin-belt continuous casting, subsequent direct rolling, intermediate annealing, cold rolling and stress-relief annealing) to systematically investigate the influence of partially substituting Er for Sc on the microstructure, mechanical properties and corrosion resistance of short-processed Al-4.7Mg-0.6Mn-0.3Zr-0.3Sc sheets. The results show that ZSE321 presents the optimal tensile properties (UTS: 541 MPa; 0.2%PS: 469 MPa and EF:7.7%) among the three experimental sheets. This is attributed to significant grain refinement, the inhibition of the recrystallization and promotion on the precipitation of Al3(Sc, Zr, Er) nanoparticles. Furthermore, the corrosion properties of the experimental sheets were also explored in this study, and the short-processed ZSE321 sheet presents the optimum corrosion resistance.

Effects of furnace temperature of stress-relief annealing on residual stress and hardness characteristics of heterogeneous materials fabricated from a DED process

Effects of furnace temperature of stress-relief annealing on residual stress and hardness characteristics of heterogeneous materials fabricated from a DED process

Research on the Influence of HMFI and PWHT Treatments on the Properties and Stress States of MAG-Welded S690QL Steel Joints.

The aim of this study was to analyze the effect of the HFMI (high-frequency mechanical impact) treatment of each weld bead on the properties of a butt joint with a ceramic backing welded by robotic method 135 (MAG-metal active gas welding method) and to determine the effect of HMFI on the stress level. This analysis was based on a comparison of three butt joints made of a S690QL plate, in the as-welded condition, with the HFMI of each bead and with the heat treatment carried out with PWHT stress relief annealing. The high-frequency (90 Hz) peening of each weld bead was linked with a stress reduction in the weld via the implementation of compressive stresses into the joint. The HFMI pneumatic hammer was used for this. The correctness of treatment was achieved when 100% of the surface of each bead including the face was treated. As part of the post-welding tests, basic tests were carried out based on the standards for the qualification of welding technology, and as a supplementary test, a stress state analysis using the Barkhausen effect was carried out. The tests carried out showed that the use of high-frequency peening after each pass did not affect the negative results of all the required tests when qualifying the welding technology of S690QL sheet metal compared to the test plates in the as-welded condition and after heat treatment-stress relief annealing. Inter-pass peening of the welded face and HAZ (heat-affected zone) resulted in a reduction in post-weld residual stresses at a distance of 12 mm from the joint axis compared to the stress measurement result for the sample in the as-welded condition. This allowed for a positive assessment of peening in the context of reducing the notch, which is the concentration of tensile stresses in the area of the fusion line and HAZ. The tests carried out showed that the peening process does not reduce the strength properties of welded joints, and the results obtained allow the technology to be qualified based on applicable standards.

Refined cyclic R-curve determination through residual crack tip stress reduction by annealing

Refined cyclic R-curve determination through residual crack tip stress reduction by annealing

Effects of stress relief annealing in NGO steels

Effects of stress relief annealing in NGO steels

A review of cooling in the industry

In modern society, metal products are needed in various industries. The annealing process is commonly employed in manufacturing. Based on the specifications of the product, the purpose of annealing is different, the annealing process specification has a variety of commonly used complete annealing, spheroidal annealing, and stress relief annealing. This paper investigates and compares the characteristics of different annealing processes in the production process through the literature research method. This paper describes seven annealing methods, mainly detailing two annealing processes, spheroidizing annealing, and recrystallization annealing, and gives examples of the advantages and disadvantages of these two processes. Annealing is primarily used to improve machinability and reduce hardness. It also stabilizes size, lowers residual stress, and lessens the tendency for deformation and cracking. Cut down on grain, reorganize, and get rid of organizational flaws, even material composition and organization can enhance a material's qualities or prepare it for upcoming heat treatments.

A Case Study: Electrically Assisted Stress Relief Annealing for Cold-Coiled Helical Automotive Springs.

This study experimentally investigated electrically assisted (EA) stress relief annealing for cold-coiled commercial automotive springs. In EA stress relief annealing, the temperature of a spring is rapidly increased to the annealing temperature (400 °C) and is held constant for a specified time using a pulsed electric current. Experimental findings show that the effectiveness of the EA stress relief annealing is superior to that of the conventional stress relief annealing, especially in terms of process time. The present study suggests that EA stress relief annealing, with properly selected process parameters, can effectively substitute for time-consuming conventional stress relief annealing using a furnace for cold-coiled automotive springs.

High-strength corrosion-resistant FeMnCr-based composite damping alloys fabricated by vacuum annealing

High-strength corrosion-resistant FeMnCr-based composite damping alloys fabricated by vacuum annealing

Delving into the intrinsic co-relation between microstructure and mechanical behaviour of fine-/ultrafine-grained TWIP steels via TEM and in-situ EBSD observation

Delving into the intrinsic co-relation between microstructure and mechanical behaviour of fine-/ultrafine-grained TWIP steels via TEM and in-situ EBSD observation

Magnetic anisotropy reduction of non-grain oriented electrical steel due to different stress relief annealing temperatures

Magnetic anisotropy reduction of non-grain oriented electrical steel due to different stress relief annealing temperatures

Evaluation of Magnetic Property in Teeth Part of Motor Core by Stress-relief Annealing with Induced Current Heating Method

Evaluation of Magnetic Property in Teeth Part of Motor Core by Stress-relief Annealing with Induced Current Heating Method

Study of microstructure and mechanical properties and residual stresses of 24CrNiMo steel prepared by selective laser melting and laser melting deposition

Study of microstructure and mechanical properties and residual stresses of 24CrNiMo steel prepared by selective laser melting and laser melting deposition

Improvement of Stress-relief Annealing Method of Motor Core with Induced Current

Improvement of Stress-relief Annealing Method of Motor Core with Induced Current