scholarly journals Microstructure Analysis and Rheological Behavior of Magnesium Alloys at Semi-solid Temperature Range

2018 ◽  
Vol 27 (9) ◽  
pp. 4593-4605 ◽  
Author(s):  
Marta Ślęzak ◽  
Piotr Bobrowski ◽  
Łukasz Rogal
2016 ◽  
Vol 95 ◽  
pp. 296-305 ◽  
Author(s):  
Xiaoguang Chen ◽  
Ruishan Xie ◽  
Zhiwei Lai ◽  
Lei Liu ◽  
Guisheng Zou ◽  
...  

2011 ◽  
Vol 213 ◽  
pp. 414-418
Author(s):  
Xing Wang Duan ◽  
Xiao Hong You ◽  
Ji Hong Tian

In this paper, the methods of electromagnetic stirring and isothermal extruding were used to study the semi-solid forming performance of ZA27 alloys. Through summarizing and analyzing the stirring experimental results, the reasonable parameter combination of electromagnetic stirring is that inputting voltage is 180V-200V and stopping stirring temperature is 465°C-475°C and cooling method is quenching. After ZA27 alloys are stirred by using above parameter combination,the spherical microstructures are obtained.Then the billets which were prepared by using above reasonable parameter combination were reheated to semi-solid temperature range for isothermal extruding.The extruding ratio was 4.Because the recrystallization occurs during extruding,the grains of ZA27 alloys become smaller and more uniform after isothermal extruding and per unit extruding force of semi-solid ZA27 alloys decreases by 1/4-1/5 times than that of general casting ZA27 alloys.These results provide a reliable experimental basis for production and application of ZA27 alloys.


2021 ◽  
Author(s):  
Stephanie Jones ◽  
Mohit Singh ◽  
Denis Duft ◽  
Alexei Kiselev ◽  
Thomas Leisner

<p>The impact of atmospheric aerosol on the climate remains poorly understood. Organic aerosol makes up a significant fraction of total aerosol and is prevalent throughout the atmosphere. It can exist as a liquid, semi-solid or amorphous solid. The viscosity of organic aerosol will have an impact on transformations that organic aerosol will undergo during its lifetime such as evaporation and growth, heterogeneous and photochemical reactions as well as the ability to act as an ice nucleating particle.  Therefore, it is of key importance to be able to determine aerosol viscosity over a range of atmospherically relevant conditions in order to better understand the impact of organic aerosol on the climate.</p> <p>Here we report proof of concept viscosity measurements of water droplets levitated in an electrodynamic balance over a range of temperatures. Charged droplets are levitated in a temperature and relative humidity-controlled environment allowing properties over a temperature range of 300 to 220 K to be studied. As the droplets evaporate they reach a point where Coulomb instabilities are induced resulting in droplet oscillations. The relaxation of these oscillations can then be probed to determine the droplet viscosity. Future work will involve determination of the viscosity of different types of organic aerosol over a broad temperature range.</p>


2022 ◽  
Vol 327 ◽  
pp. 11-25
Author(s):  
Guan Fei Xiao ◽  
Ju Fu Jiang ◽  
Ying Wang ◽  
Ying Zhe Liu ◽  
Ying Zhang ◽  
...  

Semi-solid processing combines the advantages of traditional forging and casting methods, so it has received much attention recently. However, the research on semi-solid behaviors of Nickel-based superalloys has been rarely reported. In order to investigate the behaviors of Nickel-based superalloy at solid and semi-solid states, oxidation experiments, isothermal treatment experiments and deformation experiments of GH4037 alloy were studied. Short-term oxidation experiments of GH4037 alloy were carried out at a solid temperature (1200 °C) and a semi-solid temperature (1360 °C). The results indicated that the oxides formed at 1200 °C were mainly composed of TiO2, Cr2O3 and a small amount of spinels NiCr2O4, while the oxides formed at 1360 °C consisted of the spinels of NiCr2O4, NiWO4 and NiMoO4 besides TiO2 and Cr2O3. Microstructure evolution of GH4037 alloy after semi-solid isothermal treatment at 1370 °C and 1380 °C was studied. The results indicated that semi-solid microstructures consisted of equiaxed solid grains and liquid phases. The average grains size and shape factor of solid grains were affected by melting mechanism and grain growth mechanism. Compression behaviors of GH4037 alloy after compressed at 1200 °C and 1360 °C were investigated. The results indicated that the flow stress of 1360 °C decreased significantly compared to that of 1200 °C. The deformation zones in the specimens were divided into three parts: the difficult deformation zone, the large deformation zone, and the free deformation zone. At 1200 °C, the deformation mechanism was plastic deformation mechanism. At 1360 °C, sliding between solid particles (SS), liquid flow (LF), flow of liquid incorporating solid particles (FLS), plastic deformation of solid particles (PDS) coexisted in the compression specimen.


2006 ◽  
Vol 54 (13) ◽  
pp. 3503-3511 ◽  
Author(s):  
S NAFISI ◽  
O LASHKARI ◽  
R GHOMASHCHI ◽  
F AJERSCH ◽  
A CHARETTE

2021 ◽  
Author(s):  
Himesh Patel

To improve fuel economy and reduce greenhouse gas emissions, magnesium alloys are being considered for automotive and aerospace applications because of their high strength-to-weight ratio. The objective of this thesis was to study monotonic and cyclic deformation behavior of two semi-solid processed (thixomolded) magnesium alloys, AZ91D and AM60B. The fatigue life of these thixomolded alloys was observed to be higher than that of their die cast counterparts. As the total strain amplitude increased, the stress amplitude and plastic strain amplitude increased, while the pseudoelastic modulus decreased. The change in the modulus was attributed to the nonlinear (pseudoelastic) behavior caused by twinning-detwinning during cyclic deformation. The fatigue life increased with decreasing strain ratio, and partial mean stress relaxation occurred mainly in the initial 10-20% of the fatigue life. The fatigue life of theAM60B alloy improved after solution or solution-aging treatment, and the monotonic strength increased by aging, while the thixomolded condition itself exhibited moderate monotonic strength and fatigue life.


Sign in / Sign up

Export Citation Format

Share Document