scholarly journals Effects of heat treatment on microstructure evolution and mechanical properties of Mg-6Zn-1.4Y-0.6Zr alloy

China Foundry ◽  
2017 ◽  
Vol 14 (3) ◽  
pp. 199-204 ◽  
Author(s):  
Jing Wang ◽  
Xiao-gang Fang ◽  
Shu-sen Wu ◽  
Shu-lin Lü
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Microstructure Evolution

scholarly journals Microstructure Evolution and Mechanical Properties of AZ80 Mg Alloy during Annular Channel Angular Extrusion Process and Heat Treatment

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4223 ◽  
Author(s):  
Xi Zhao ◽  
Shuchang Li ◽  
Fafa Yan ◽  
Zhimin Zhang ◽  
Yaojin Wu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Microstructure Evolution ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Annular Channel ◽  
Mg Alloy ◽  
Strengthening Effect ◽  
Β Phase ◽  
Angular Extrusion

Microstructure evolution and mechanical properties of AZ80 Mg alloy during annular channel angular extrusion (350 °C) and heat treatment with varying parameters were investigated, respectively. The results showed that dynamic recrystallization of Mg grains was developed and the dendritic eutectic β-Mg17Al12 phases formed during the solidification were broken into small β-phase particles after hot extrusion. Moreover, a weak texture with two dominant peaks formed owing to the significant grain refinement and the enhanced activation of pyramidal <c + a> slip at relative high temperature. The tension tests showed that both the yield strength and ultimate tensile strength of the extruded alloy were dramatically improved owing to the joint strengthening effect of fine grain and β-phase particles as compared with the homogenized sample. The solution treatment achieved the good plasticity of the alloy resulting from the dissolution of β-phases and the development of more equiaxed grains, while the direct-aging process led to poor alloy elongation as a result of residual eutectic β-phases. After solution and aging treatment, simultaneous bonding strength and plasticity of the alloy were achieved, as a consequence of dissolution of coarse eutectic β-phases and heterogeneous precipitation of a large quantity of newly formed β-phases with both the morphologies of continuous and discontinuous precipitates.

scholarly journals Isochronal Phase Transformation in Bimodal Ti-55531

Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 790 ◽  
Author(s):  
Fuwen Chen ◽  
Guanglong Xu ◽  
Kechao Zhou ◽  
Hui Chang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Activation Energy ◽  
Phase Transformation ◽  
Microstructure Evolution ◽  
Continuous Heating ◽  
Interface Curvature ◽  
The Difference ◽  
Treatment Procedures ◽  
And Control

Bimodal microstructures where globular α and acicular α phases are embedded in the β matrix are commonly used in industry-relevant Ti-55531. To optimize the performance of Ti-55531 through heat treatment, it is crucial to understand and control the phase transformation in the as-received bimodal Ti-55531 as well as its microstructure evolution. In this work, the isochronal phase transformations and microstructure evolution in the bimodal Ti-55531 during the continuous heating were systematically studied by combining dilatometry, XRD phase analyses, and SEM observation. The β → α transformation occurred at 678 K only with the acicular α. When the temperature was higher than 788 K, α → β transformation took place in two separate stages (i.e., αacicular → β and αglobular → β transformation). The dissolution of αglobular occurred after the dissolution of αacicular was completed. Due to the difference in the chemical composition and interface curvature between αacicular and αglobular, the average activation energy for αacicular → β transformation was lower than that for the αglobular → β transformation. The isochronal phase transformation and microstructure evolution during continuous heating in the present work could be used to optimize heat treatment procedures for desired mechanical properties.

scholarly journals Microstructure evolution and mechanical properties of rheo-squeeze casting AZ91-Ca alloy during heat treatment

China Foundry ◽  
2017 ◽  
Vol 14 (6) ◽  
pp. 485-491 ◽  
Author(s):  
Yang Zhang ◽  
Xiao-ping Li ◽  
Shun-ping Sun ◽  
Ya-lin Lu ◽  
Guo-hua Wu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Microstructure Evolution ◽  
Squeeze Casting

scholarly journals Microstructure Evolution and Mechanical Properties of 0.4C-Si-Mn-Cr Steel during High Temperature Deformation

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 172 ◽  
Author(s):  
Fei Zhang ◽  
Yang Yang ◽  
Quan Shan ◽  
Zulai Li ◽  
Jinfeng Bi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Temperature ◽  
Impact Toughness ◽  
Microstructure Evolution ◽  
Cast Steel ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Grain Sizes ◽  
The Impact

Herein, the effects of height-diameter ratios (H/D) on the microstructure evolution and mechanical properties of 0.4C-Si-Mn-Cr steel during high temperature deformation are reported. The compression experiments were performed on steel samples using Gleeble to obtain a reasonable deformation temperature, and the degree of deformation was assessed in the range of 1.5 to 2.0 H/D via forging. The forged specimens were quenched using the same heat treatment process. The hardness and impact toughness of the steel samples were tested before and after heat treatment. Grain sizes gradually increased with an increase in the compression temperature from 950 °C to 1150 °C, and the grain sizes decreased with an increase in H/D. The microstructure of the steel samples contained pearlite, bainite, martensite, and retained austenite phase. The microstructure after forging was more uniform and finer as compared to that of as-cast steel samples. The hardness and impact toughness of the steel samples were evaluated after forging; hardness first increased and then decreased with an increase in H/D, while the impact toughness continuously increased with an increase in H/D. Hence, the microstructure and properties of steel could be improved via high temperature deformation, and this was primarily related to grain refinement.

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