Impact of asymmetry deformation on microstructure and mechanical properties of AZ31B alloy sheets deformed by on-line heating rolling

A novel on-line vortex cooling powered by low-cost compressed air was proposed to reduce common defects such as low forming precision, coarse grains, and pores caused by heat accumulation in the Wire Arc Additive Manufacturing (WAAM) of aluminum alloy. The impacts of interlayer cooling (IC), substrate cooling (SC), on-line cooling (OL), and natural cooling (NC) processes were compared on the morphology, microstructure, and mechanical properties of as-deposited walls, revealing that the OL process significantly lowers the interlayer temperature and improves forming precision. The high cooling rate produced by the OL process reduced the absorption of hydrogen in the molten pool, lowering porosity. Furthermore, the grains are refined due to the developed undercooling. However, the high cooling rate enhanced the segregation potential of Mg element and raised the content of the β phase. Conclusively, the maximum tensile strength, elongation, and microhardness of the as-deposited wall are achieved via the OL process, and the fine-grain strengthening mechanism plays an important role in improving mechanical properties. The OL process is cheaper and poses a significant effect; it is highly suitable for the additive manufacturing of complex components compared with other forced cooling processes.

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Microstructure and Mechanical Properties of J55ERW Steel Pipe Processed by On-Line Spray Water Cooling

Metals ◽

10.3390/met7040150 ◽

2017 ◽

Vol 7 (4) ◽

pp. 150 ◽

Cited By ~ 2

Author(s):

Zejun Chen ◽

Xin Chen ◽

Tianpeng Zhou

Keyword(s):

Mechanical Properties ◽

Steel Pipe ◽

Water Cooling ◽

Microstructure And Mechanical Properties ◽

On Line

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The Edge Crack, Texture Evolution, and Mechanical Properties of Mg-1Al-1Sn-Mn Alloy Sheets Prepared Using On-Line Heating Rolling

Metals ◽

10.3390/met8100860 ◽

2018 ◽

Vol 8 (10) ◽

pp. 860 ◽

Cited By ~ 5

Author(s):

Qiang Liu ◽

Jiangfeng Song ◽

Fusheng Pan ◽

Jia She ◽

Shuo Zhang ◽

...

Keyword(s):

Mechanical Properties ◽

Electron Backscatter Diffraction ◽

Texture Evolution ◽

Rolling Direction ◽

Rolling Temperature ◽

Line Heating ◽

Basal Pole ◽

On Line ◽

Edge Cracks ◽

Conventional Rolling

A series of Mg-1Al-1Sn-Mn magnesium alloy sheets were rolled from 3 mm to 1 mm under temperatures of 150 °C, 200 °C, and 250 °C in four rolling passes using on-line heating rolling. The conventional rolling was also performed for comparison. Scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) technologies were utilized to characterize the edge cracks as well as the microstructure of rolled thin sheets. The result revealed that the number of edge cracks decreased dramatically with the increase of rolling temperature. No visible edge cracks were found on the surface of sheets rolled at 250 °C by on-line heating rolling, while the conventional rolling at the same temperature still resulted in severe edge cracks. The intensity of the basal texture for on-line rolled sheets increased from 4.982 to 9.596 as the rolling temperature increased from 150 °C to 250 °C, which was related to the reorientation of new grains and deformation grains remained after rolling. The direction of the basal pole slightly tilted towards the rolling direction (RD), which may be mainly attributed to the activation of a pyramidal slip, as well as the tension imposed on the samples. Moreover, mechanical properties were improved after rolling on the basis of the strong texture and grain refinement. The highest yield strength (YS), ultimate tensile strength (UTS), and the maximum elongation of the rolled sheets were 148 MPa, 298 MPa, and 14.6% along the RD, respectively.

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