Microstructure and Mechanical Properties of Hyper-Interfacial Bonded Joints of Ultra-Fine Grained High Strength Steels

2005 ◽  
pp. 437-442
Author(s):  
Kazutoshi Nishimoto ◽  
Kazuyoshi Saida ◽  
Boyoung Jeong
Keyword(s):  
Mechanical Properties ◽  
High Strength Steels ◽  
High Strength ◽  
Bonded Joints ◽  
Fine Grained ◽  
Microstructure And Mechanical Properties

scholarly journals Effect of ECAP on the Microstructure and Mechanical Properties of a Rolled Mg-2Y-0.6Nd-0.6Zr Magnesium Alloy

Crystals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 586 ◽  
Author(s):  
Shi ◽  
Li ◽  
Hu ◽  
Tan ◽  
Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Room Temperature ◽  
High Strength ◽  
Electron Backscattered Diffraction ◽  
Bar Rolling ◽  
Fine Grained ◽  
Angular Pressing ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size

A fine-grained Mg-2Y-0.6Nd-0.6Zr alloy was processed by bar-rolling and equal-channel angular pressing (ECAP). The effect of ECAP on the microstructure and mechanical properties of rolled Mg-2Y-0.6Nd-0.6Zr alloy was investigated by optical microscopy, scanning electron microscopy, electron backscattered diffraction and a room temperature tensile test. The results show that the Mg-2Y-0.6Nd-0.6Zr alloy obtained high strength and poor plasticity after rolling. As the number of ECAP passes increased, the grain size of the alloy gradually reduced and the texture of the basal plane gradually weakened. The ultimate tensile strength of the alloy first increased and then decreased, the yield strength gradually decreased, and the plasticity continuously increased. After four passes of ECAP, the average grain size decreased from 11.2 µm to 1.87 µm, and the alloy obtained excellent comprehensive mechanical properties. Its strength was slightly reduced compared to the as-rolled alloy, but the plasticity was greatly increased.

scholarly journals Microstructure and Mechanical Properties of Spark Plasma Sintered and Severely Deformed AA7075 Alloy

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1433
Author(s):  
Dariusz Garbiec ◽  
Volf Leshchynsky ◽  
Andrea García-Junceda ◽  
Radosław Swadźba ◽  
Piotr Siwak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Dynamic Recrystallization ◽  
Grain Boundaries ◽  
Shear Bands ◽  
High Strength ◽  
Ultrafine Grain ◽  
Fine Grained ◽  
Severe Deformation ◽  
Microstructure And Mechanical Properties ◽  
Spark Plasma

In this paper, the microstructure and mechanical properties of AA7075 with a coarse-fine-grained laminated microstructure produced by spark plasma sintering (SPS) and the cyclic extrusion severe deformation (KOBO) technique were investigated. It was found that an inhomogeneous grain microstructure was formed from coarse and fine grains by the SPS process and then was transformed into a coarse-fine-grained laminated microstructure by means of KOBO extrusion at room temperature. The grain refinement during KOBO extrusion resulted in a fine grained laminated microstructure created due to the formation of low-angle grain boundaries (LAGBs), followed by dynamic recrystallization, leading to high-angle grain boundaries (HAGBs). The EBSD analysis results reveal the formation of a deformed and partially recrystallized ultrafine grain microstructure owing to the generation and development of shear bands during KOBO extrusion. The ultimate tensile strength (UTS) of the AA7075 alloy rose after SPS-KOBO severe deformation up to 422 MPa, with high strains of about 33%. The obtained results clearly show that the SPS-KOBO extrusion technique allows a bimodal laminated fine gradient grain microstructure to be obtained due to deformation and dynamic recrystallization, which result in both high strength and good ductility. The new heterogeneous AA7075 alloys obtained by the SPS-KOBO combined techniques demonstrate that microstructural heterogeneities can assist in overcoming the strength–ductility trade-off.

scholarly journals Controlling microstructure and mechanical properties of additively manufactured high-strength steels by tailored solidification

2020 ◽  
Vol 35 ◽  
pp. 101389
Author(s):  
Patrick Köhnen ◽  
Simon Ewald ◽  
Johannes Henrich Schleifenbaum ◽  
Andrey Belyakov ◽  
Christian Haase
Keyword(s):  
Mechanical Properties ◽  
High Strength Steels ◽  
High Strength ◽  
Microstructure And Mechanical Properties

scholarly journals Effect of Heat Input and Undermatched Filler Wire on the Microstructure and Mechanical Properties of Dissimilar S700MC/S960QC High-Strength Steels

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 883 ◽  
Author(s):  
Francois Njock Bayock ◽  
Paul Kah ◽  
Belinga Mvola ◽  
Pavel Layus
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Heat Affected Zone ◽  
Heat Input ◽  
Volume Fraction ◽  
Base Material ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Microstructure And Mechanical Properties

The effect of heat input on the microstructure and mechanical properties of dissimilar S700MC/S960QC high-strength steels (HSS) using undermatched filler material was evaluated. Experiments were performed using the gas metal arc welding process to weld three samples, which had three different heat input values (i.e., 15 kJ/cm, 7 kJ/cm, and 10 kJ/cm). The cooling continuous temperature (CCT) diagrams, macro-hardness values, microstructure formations, alloy element compositions, and tensile test analyses were performed with the aim of providing valuable information for improving the strength of the heat-affected zone (HAZ) of both materials. Micro-hardness measurement was conducted using the Vickers hardness test and microstructural evaluation by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The mechanical properties were characterized by tensile testing. Dissimilar welded samples (S700MC/S960QC) with a cooling rate of 10 °C/s (15 kJ/cm) showed a lower than average hardness (210 HV5) in the HAZ of S700MC than S960QC. This hardness was 18% lower compared to the value of the base material (BM). The best microstructure formation was obtained using a heat input of 10 kJ/cm, which led to the formation of bainite (B, 60% volume fraction), ferrite (F, 25% volume fraction), and retained austenite (RA, 10%) in the final microstructure of S700MC, and B (55%), martensite (M, 45%), and RA (10%), which developed at the end of the transformation of S960QC. The results showed the presence of 1.3 Ni, 0.4 Mo, and 1.6 Mn in the fine-grain heat-affected zone of S700MC. The formation of a higher carbide content at a lower cooling rate reduced both the hardness and strength.

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