Extrusion of Hollow Magnesium Profiles and Investigation of Extrusion Seams

Gensch, Felix; Nitschke, Renè; Gall, Sven; Müller, Sören

doi:10.1002/9781118888179.ch49

Cited by 2 publications

(6 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the weld-free material, the split of the basal pole and accompanying tilt of c-axes of most grains of around 30°towards the ED enables the easy activation of basal hai-slip. This results in lower values for the tensile yield strength (TYS) in ED than in TD and is consistent with previous findings [9,13].…”

Section: Mechanical Propertiessupporting

confidence: 93%

“…Optical micrographs revealed that the width of this heavy-sheared region is approximately 1.5 mm. The XRD measurements in [9] incorporate a larger area of material, which was not affected by the heavy shearing attributed to the pole figure.…”

Section: Microstructure Of the Weld Seamsmentioning

confidence: 98%

“…Up to now, only few investigations on the formation of weld seams in magnesium hollow extrusions and its impact on the product properties are performed [3,8,9]. It is not known, if and how the local microstructure alteration in the weld seams influences the mechanical properties.…”

Section: Introductionmentioning

confidence: 99%

“…With increasing extrusion ratio, {0001}-planes are oriented more parallel towards the normal direction. Gensch et al[9] reported about XRD texture analysis on the welding area of a ME21 hollow profiles (ER = 37:1) delivering broadening of the pole density towards TD. That finding was in contrast to the usual texture of an ME21 sheet with the basal planes oriented…”

mentioning

confidence: 99%

See 3 more Smart Citations

Characterization of weld seam properties of extruded magnesium hollow profiles

et al. 2016

Self Cite

View full text Add to dashboard Cite

Extrusions of hollow profiles with weld seams were conducted using the magnesium alloy ME21 applying various extrusion ratios. Subsequent analysis of the profiles' microstructure was performed comparing weld free with weld seam containing material using (polarized) light optical microscopy (LOM). Additionally, the local texture and microstructure in the weld-free material as well as in the weld seam region has been examined with a scanning electron microscope coupled with electron backscatter diffraction technique (SEM-EBSD). The weld-free material and the weld seam are characterized by recrystallized microstructures, whereas few residual cast grains were identified. The local texture distinctively changes from the weld-free material to the weld seam. The texture of the weld-free material is comparable with the typical ME21 sheet texture. In the weld seam area, a pole density is found, which is distributed towards the transverse direction (TD) combined with a split and broadening of the pole density in the extrusion direction (ED). This texture influences the mechanical anisotropy due to the dependence of the activation of basal hai-slip and f1012g h10 11i-extension twinning on the loading direction in favorably oriented grains.

show abstract

Section: Mechanical Propertiessupporting

confidence: 93%

Section: Microstructure Of the Weld Seamsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Characterization of weld seam properties of extruded magnesium hollow profiles

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…The authors in Reference [28] found larger grains in weld seams of extruded AZ31 hollow profiles compared to the weld-free microstructure. In contrast, in the work of References [29,30], the grains in the welding zone of extruded AZ31 hollow profiles was smaller, with the difference being that the latter profiles were extruded at significantly lower temperatures.…”

Section: Introductionmentioning

confidence: 99%

Microstructural Stability of Extruded Mg-Mn-Ce Hollow Profiles with Weld Seams

Gensch¹,

Gall²,

Lechner

et al. 2021

Metals

View full text Add to dashboard Cite

Despite aluminum profiles, magnesium profiles have not been well developed due to the low formability. Furthermore, extruded magnesium profiles show a strong dependence on the mechanical properties, according to the loading direction. This is caused by a strong basal texture, which is directly dependent on the process parameters during the extrusion and the subsequent aging. Thus, the present paper focuses on the analysis of the microstructure and its evolution of extruded magnesium hollow profiles, which were subjected to a series of heat treatments at 475 °C up to one hour. The hollow profiles were extruded through a porthole die, thus, containing longitudinal weld seams. These were formed by material that underwent heavy shearing along the tool surface based on the friction conditions in the porthole die. Three extrusion ratios (ER = 8:1, ER = 16:1, ER = 30:1) were applied, resulting in three different wall thicknesses of the profiles. The microstructure of the profiles was analyzed using light-optical microscopy (LOM) and scanning electron microscopy (SEM) coupled with electron backscatter diffraction (EBSD). The analysis revealed no change of the microstructure of the profiles extruded at the two higher extrusion ratios within the time frame of the heat treatment. In contrast, the microstructure and, thus, the micro-texture of the profile with the lowest extrusion ratio (ER = 8:1) has been affected to a great extent. While only small changes in microstructure in the weld-free area were observed, the initial microstructure in the weld seam was transformed from fine recrystallized grains into a significantly bimodal microstructure mainly due to an abnormal grain growth (AGG). These changes were accompanied by a promotion of the rare-earth (RE) texture component for the weld-free material and a change of the overall texture from RE to a typical non-RE double fiber texture for the weld seam due to the intense AGG within the short-time heat treatments. In addition, the influence of the extrusion ratio on particle size and distribution as well as the character of the microstructure governing the behavior during heat treatments was analyzed and discussed.

show abstract

Extrusion of Hollow Magnesium Profiles and Investigation of Extrusion Seams

Cited by 2 publications

References 16 publications

Characterization of weld seam properties of extruded magnesium hollow profiles

Characterization of weld seam properties of extruded magnesium hollow profiles

Microstructural Stability of Extruded Mg-Mn-Ce Hollow Profiles with Weld Seams

Contact Info

Product

Resources

About