Acceleration of aging behavior and improvement of mechanical properties of extruded AZ80 alloy through (10–12) twinning

In the field of polymer technology, a variety of mainly synthetic additives are used to stabilize the materials during processing. However, natural compounds of plant origin can be a green alternative to chemicals such as synthetic polyphenols. An analysis of the effect of hesperidin on the aging behavior of ethylene-norbornene copolymer was performed. The evaluation of changes in the tested samples was possible by applying the following tests: determination of the surface energy and OIT values, mechanical properties analysis, colour change measurements, FT-IR and TGA analyses. The obtained results proved that hesperidin can be effectively used as natural stabilizer for polymers. Furthermore, as a result of this compound addition to Topas-silica composites, their surface and physico-mechanical properties have been improved and the resistance to aging significantly increased. Additionally, hesperidin can act as a dye or colour indicator and only few scientific reports describe a possibility of using flavonoids to detect changes in products during their service life, e.g., in food packaging. In the available literature, there is no information about the potential use of hesperidin as a stabilizer for cycloolefin copolymers. Therefore, this approach may contribute not only to the current state of knowledge, but also presents an eco-friendly solution that can be a good alternative to synthetic stabilizers.

Download Full-text

Microstructures, mechanical properties, and aging behavior of hybrid-sized TiB2 particulate-reinforced 2219 aluminum matrix composites

Materials Science and Engineering A ◽

10.1016/j.msea.2021.142180 ◽

2021 ◽

pp. 142180

Author(s):

Linwei Li ◽

Zhenhao Han ◽

Minqiang Gao ◽

Shaowei Li ◽

Huihui Wang ◽

...

Keyword(s):

Mechanical Properties ◽

Aluminum Matrix ◽

Aluminum Matrix Composites ◽

Matrix Composites ◽

Aging Behavior ◽

Particulate Reinforced

Download Full-text

Effect of Plastic Deformation on the Mechanical Properties and Microstructure of Homogenized AZ80 Magnesium Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.139-141.180 ◽

2010 ◽

Vol 139-141 ◽

pp. 180-184

Author(s):

Yong Xue ◽

Zhi Min Zhang ◽

Li Hui Lang

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Grain Boundaries ◽

Gradual Increase ◽

Tensile Tests ◽

Extrusion Ratio ◽

Extrusion Temperature ◽

Second Phase ◽

Strength And Plasticity ◽

Az80 Alloy

In the present research, the influences of different extrusion ratios (15, 30, 45, 60, and 75) and extrusion temperatures (300°C, 330°C, 360°C, 390°C, 420°C) on the mechanical properties and microstructure of homogenized AZ80 alloy have been investigated through the tensile tests and via metallographic microscope observation. The results show that the alloy’s grain is small and small amounts of black hard and brittle second-phase β (Mg17Al12) are precipitated uniformly along the grain boundary causing the gradual increase of the alloy’s tensile strength at 330°C. When the extrusion temperature is up to 390°C, the grain size increases significantly, but the second phase precipitation along grain boundaries transforms into continuous and uniform-distribution precipitation within the grain. In this case, when the extrusion ratio is 60, the alloy’s tensile strength reaches its peak 390Mpa. As the extrusion temperature increases, inhomogeneous precipitation of the second-phase along grain boundaries increases, causing the decrease of the alloy’s strength. At the same temperature, the tensile strength increases firstly and then decreases as extrusion ratio increases. With the gradual increase of the refinement grain, the dispersed precipitates increase and the alloy’s tensile strength and plasticity reach their peaks when the extrusion temperature is 390°C. As the grain grows, the second phase becomes inhomogeneous distribution, and the alloy’s strength and plasticity gradually decrease.

Download Full-text

Investigation on the Stress Relaxation Aging Behavior of 2195 Al-Li Alloy

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.315.37 ◽

2021 ◽

Vol 315 ◽

pp. 37-42

Author(s):

Hai Long Liao ◽

Li Hua Zhan ◽

Yuan Gao ◽

Xue Ying Chen ◽

Ming Hui Huang

Keyword(s):

Mechanical Properties ◽

Stress Relaxation ◽

High Performance ◽

Aging Process ◽

Artificial Aging ◽

Ageing Time ◽

High Strength ◽

Aging Behavior ◽

Stress Corrosion Resistance ◽

Scanning Electron

2195 Al-Li alloy is famous for high strength, excellent fatigue strength and good stress corrosion resistance, which is widely used in the manufacture of high-performance aerospace components. The aim of this study is to validate how the stress relaxation aging behavior effect on the mechanical properties of 2195 Al-Li alloy. Through mechanical property test, the research was found that the performance after stress relaxation aging is higher than artificial aging (AA). In addition, the analysis of scanning electron microscopy SEM and TEM revealed that dislocations should be introduced by the stress relaxation aging process, which is more conducive to the precipitation of the T1 phase and strengthened the material with prolong ageing time. The results show that stress relaxation aging can significantly promote the precipitation of the T1. Therefore, this paper sheds new light on how SRA can improve mechanical properties and that SRA make better improve the distribution of precipitates in the grain boundary.

Download Full-text

Effect of the Mg3N2 Sub-Micron Particle on the Grain Refinement of AZ80 Alloy

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.327.45 ◽

2022 ◽

Vol 327 ◽

pp. 45-53

Author(s):

Jiehua Li ◽

Maria Pammer ◽

Ernst Neunteufl ◽

Peter Schumacher

Keyword(s):

Mechanical Properties ◽

Grain Size ◽

Grain Refinement ◽

Liquid State ◽

High Performance ◽

Great Loss ◽

Micron Particle ◽

Deformation Ability ◽

Semi Solid ◽

Az80 Alloy

AZ80 alloy has been widely used to produce high performance Mg casting and wrought parts for high-end applications due to its high mechanical properties and deformation ability. However, at least two important issues still need to be solved in order to further improve its mechanical properties and deformation ability. Firstly, the grain size of α-Mg in AZ80 alloy is relatively large (more than 1000 µm) due to a lack of efficient grain refinement methodologies. Secondly, the size of the eutectic Mg17Al12 phase is also large and the distribution of the eutectic Mg17Al12 phase is continuous, which is very harmful for the mechanical properties, in particular to elongation. In this paper, these two important issues are investigated by adding Mg3N2 sub-micron particle into AZ80 alloy and thereby refining the α-Mg and the eutectic Mg17Al12 phase. Firstly, the Mg3N2 sub-micron particle was directly added into AZ80 alloy by using mechanically stirring in the semi-solid state, subsequently the melting temperature was increased above the liquidous temperature, and finally the melting was casted in the liquid state. It was found that the grain size of α-Mg can be refined from 883.8 µm to 169.9 µm. More importantly, the eutectic Mg17Al12 phase was also refined and the distribution became discontinuous. It should be noted that directly adding the Mg3N2 sub-micron particle into AZ80 alloy leads to a great loss of the Mg3N2 sub-micron particle due to the weak wetting behavior between the Mg3N2 sub-micron particle and Mg melt. The second methodology through mixing Mg3N2 sub-micron particles with AZ91 chips using a twin extruder was also used to prepare AZ91 master alloy with 3wt.% Mg3N2 sub-micron particle, which was subsequently added into AZ80 alloy in the liquid state. In this way, a significant grain refinement of α-Mg and a simultaneous refinement of the eutectic Mg17Al12 phase in AZ80 alloy was also achieved. The grain size of α-Mg can be refined from 883.8 µm to 325.9 µm. However, no significant grain refinement by using UST was observed. Instead, the grain size increases from 325.9 µm to 448.6 µm, indicating that the Mg3N2 sub-micron particle may lose its grain refinement potency due to possible aggregation and clustering. This paper provides an efficient and simple methodology for the grain refinement of α-Mg and the simultaneous refinement of the eutectic Mg17Al12 phase in AZ80 alloy.

Download Full-text

Effect of Ce Addition on Modifying the Microstructure and Achieving a High Elongation with a Relatively High Strength of As-Extruded AZ80 Magnesium Alloy

Materials ◽

10.3390/ma12010076 ◽

2018 ◽

Vol 12 (1) ◽

pp. 76 ◽

Cited By ~ 6

Author(s):

Zheng Wang ◽

Jin-Guo Wang ◽

Ze-Yu Chen ◽

Min Zha ◽

Cheng Wang ◽

...

Keyword(s):

Mechanical Properties ◽

Dynamic Recrystallization ◽

Grain Refinement ◽

High Strength ◽

Tensile Tests ◽

Area Fraction ◽

Schmid Factor ◽

High Elongation ◽

Az80 Alloy ◽

Ce Content

Forming magnesium alloys with rare earth elements (La, Gd, Nd, Y, Ce) is a routine method for modifying their microstructure and properties. In the present work, the effect of Ce addition on the microstructure evolution and the mechanical properties of as-extruded Mg-8Al-0.5Zn (AZ80) alloy was investigated. All of the extruded AZ80-xCe (x = 0, 0.2, 0.8 and 1.4 wt %) alloys exhibited equiaxed grains formed by fully dynamic recrystallization, and the grain size of the extruded AZ80 alloy was remarkably reduced by ~56.7% with the addition of 1.4 wt % Ce. Furthermore, the bulk-shaped Al4Ce phase formed when Ce was first added, with the Ce content rising to 0.8 wt % or higher, and Al4Ce particles in both the nano- and micron sizees were well distributed in the primary α-Mg matrix. The area fraction of the Al4Ce particles expanded with increasing Ce content, providing more nuclei for dynamic recrystallization, which could contribute to the grain refinement. The results of the tensile tests in this study showed that Ce addition effectively improved the room temperature formability of the as-extruded AZ80 alloy, without sacrificing strength. The significantly improved mechanical properties were ascribed to excellent grain refinement, weakened texture strength, an increased Schmid factor, and a reduced area fraction of low-angle grain boundaries, all resulting from Ce addition to the as-extruded AZ80 alloy. The contribution of the nano-Al4Ce precipitates on improving the mechanical properties was also discussed in this paper.

Download Full-text

Effects of abnormal grain growth at longitudinal weld on the aging behavior and mechanical properties of 2196 Al-Cu-Li alloy profile

Materials & Design ◽

10.1016/j.matdes.2021.110043 ◽

2021 ◽

pp. 110043

Author(s):

Xiao Xu ◽

Xinwu Ma ◽

Guoqun Zhao ◽

Yongxiao Wang ◽

Xiaoxue Chen

Keyword(s):

Mechanical Properties ◽

Grain Growth ◽

Abnormal Grain Growth ◽

Aging Behavior

Download Full-text

Aging Behavior of Al-Cu Alloys Produced by Melt Extrusion Process

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.116-117.550 ◽

2006 ◽

Vol 116-117 ◽

pp. 550-553

Author(s):

Byoung Soo Lee ◽

Dae Heon Joo ◽

Hoon Cho ◽

Hyung Ho Jo ◽

Myung Ho Kim

Keyword(s):

Mechanical Properties ◽

Extrusion Process ◽

Semisolid State ◽

Aging Behavior ◽

Melt Extrusion ◽

Cu Alloy ◽

Cu Alloys ◽

Metallic Melt ◽

Mean Grain Size ◽

The Mean

Melt extrusion is a new fabrication process with the characteristics of both casting and extrusion. In this process, a metallic melt which is poured and solidified up to semisolid state in the container can be directly extruded through the die exit to form a product of bar shape without other intermediate processes. The aging behavior of Al-Cu alloys in the semisolid state was investigated. And the microstructure and mechanical properties of the melt extruded Al-Cu alloy bar were measured and its characteristics are compared with those of a hot extruded Al-Cu alloy bar. Al-Cu alloys were successfully extruded after squeezing out of liquid during melt extrusion with smaller force compared to the solid extrusion. Al-Cu alloys bar with the mean grain size of up to 200 μm was fabricated by melt extrusion process. And the mechanical properties of the melt extruded Al-Cu alloy bar were improved after the T6 treatment.

Download Full-text