The effect of grain size on the tensile properties of high-purity molybdenum at room temperature

1959 ◽  
Vol 4 (38) ◽  
pp. 194-199 ◽  
Author(s):  
A. A. Johnson
2012 ◽  
Vol 706-709 ◽  
pp. 3046-3051
Author(s):  
Comondore Ravindran ◽  
Sophie Lun Sin

This Research Focused on Studying the Effect of Silicon on the Hot Tearing Susceptibility of Permanent Mould Cast AZ91E Magnesium Alloy. Varying Amounts of Silicon (0.5, 1.0 and 1.5 Wt.%) Were Added to AZ91E in the Form of an Al-53 Wt.% Si Master Alloy. the Microstructure, Grain Size and Solidification Behavior of each Alloy Were Characterized and Related to their Tensile Properties and Hot Tearing Susceptibility. the Results Showed that the Tensile Strength and the Elongation of AZ91 Alloy Decreased with the Addition of Silicon at Room Temperature, due to the Formation of Chinese Script Mg2si Particles. however, Silicon Significantly Reduced the Hot Tearing Susceptibility of AZ91E. this Was Attributed to the Reduction of the Grain Size and the Decreased Freezing Range of AZ91E, which Contributed to Improve the Interdendritic Feeding during the Last Stage of Solidification.


2010 ◽  
Vol 97-101 ◽  
pp. 153-157
Author(s):  
Tao Wang ◽  
Hong Zhen Guo ◽  
Jian Hua Zhang ◽  
Ze Kun Yao

The microstructures and room temperature and 600°C tensile properties of Ti-5.8Al-4.0Sn-4.0Zr-0.7Nb -0.4Si-1.5Ta alloy after isothermal forging have been studied. The forging temperature range was from 850°C to 1075°C, and the constant strain rate of 8×10-3/S-1 was adopted. With the increase of forging temperature, the volume fraction of primary α phase decreased and the lamellar α phase became thicker when the temperatures were in range of 850°C -1040°C; The grain size became uneven and the α phase had different forms when the forging temperature was 1040°C and 1075°C respectively; The tensile strength was not sensitive to the temperature and the most difference was within 20MPa. Tensile strength and yield strength attained to the maximum when temperature was 1020°C; the ductility decreased with the increase of forging temperature, and this trend became more obvious if forging temperature was above the β-transus temperature.


2014 ◽  
Vol 89 ◽  
pp. 88-93
Author(s):  
Marek Boniecki ◽  
Zdzislaw Librant ◽  
Władysław Wesołowski ◽  
Magdalena Gizowska ◽  
Marcin Osuchowski ◽  
...  

Fracture toughness KIc and four-point bending strength σc at high temperature (up to 1500 °C) of Y2O3 ceramics of various grain size were measured. The ceramics were prepared by pressureless air sintering and next hot isostatic pressing of high purity (99.99%) Y2O3 powder. Relative density of about 99 % was achieved. Photos of microstructures revealed small pores distributed mainly inside grains. For smallest grain size (2 - 9 μm) ceramics KIc and σc are almost constant from 20 ° to 1200 °C and next they decrease. For biggest grain size (about 44 μm) they increase up to 800 °C and next they keep constant up to 1200 °C. The micrographs analyses of fracture surfaces indicated that transgranular mode of fracture at room temperature changes to almost intergranular at higher temperatures.


2014 ◽  
Vol 941-944 ◽  
pp. 59-65
Author(s):  
Jia Wei Yuan ◽  
Xing Gang Li ◽  
Kui Zhang ◽  
Yong Jun Li ◽  
Ming Long Ma ◽  
...  

The effect of mixed RE elements (Y, Nd, Gd ) on the microstructure and tensile properties of die-cast AZ91D alloy were investigated. The results indicated that the content of mixed RE elements lead to the change of the formation of Al▔RE compounds and reduction of the fraction of β-Mg17Al12 phase. The grain size of the alloy added 1.0wt. % RE became smaller than die-cast AZ91D and AZ91D+2.0wt. % RE alloys. The UTS of die-cast AZ91D+xRE(x=0 wt. %, 1.0wt. %, 2.0 wt. %) alloys were 204MPa, 194MPa, 203.6MPa at room temperature, respectively. Moreover, RE addition resulted in fracture behaviors changed.


2012 ◽  
pp. 198-213 ◽  
Author(s):  
Jean-Roch Vaunois ◽  
Jonathan Cormier ◽  
Patrick Villechaise ◽  
Alexandre Devaux ◽  
Benjamin Flageolet

2011 ◽  
Vol 189-193 ◽  
pp. 3789-3794 ◽  
Author(s):  
Wen Zhong Jin ◽  
Wei Zhang ◽  
Ting Ju Li ◽  
Guo Mao Yin

The effects of rotating electromagnetic stirring and inoculants on the solidification structures and properties of IN100 superalloy vacuum investment casting was studied with XRD, SEM and optical microscope. The results show that by initiating the 50Hz, 150A rotating electromagnetic stirring as soon as the molten metal was poured into the mould, which was coated with inoculant CoAl2O4, the average equiaxed grain size of IN100 superalloy vacuum investment casting can be refined to 95μm and the fraction of equiaxed grains can be increased to 99 %. On condition that the grain size of K417 superalloy vacuum investment casting were refined to 95μm, the tensile properties at room temperature, the morphology of (γ+γ′)eutectic and the morphology of dendrites can be greatly improved.


2016 ◽  
Vol 849 ◽  
pp. 114-120
Author(s):  
Xiao Hui Feng ◽  
Hong Min Jia ◽  
Yun Teng Liu ◽  
Yang De Li ◽  
Wei Rong Li ◽  
...  

The microstructure, tensile properties at room temperature and corrosion rate in the 0.9% NaCl solution of the as-cast, as-extruded and as-drawn high-purity magnesium (99.99wt.% Mg) were experimentally investigated, respectively. Due to the coarse grains, both the tensile properties and corrosion resistance of the as-cast high-purity Mg were the lowest among the three states specimens, the yield strength (YS), ultimate tensile strength (UTS) and the elongation (EL) were 26.6MPa, 69.2MPa and 5.6%, respectively. The mass-loss rate of the as-cast high-purity Mg in the NaCl solution was 0.44g⋅m-2⋅h-1. For the as-extruded high-purity Mg, as the grains was remarkably refined, the YS, UTS and EL increased to be 108.3MPa, 152.7MPa and 27.0%, respectively, and the mass-loss rate become slower to be 0.25g⋅m-2⋅h-1. Attributed to the further refined grains, the YS, UTS and EL of the as-drawn high-purity Mg increased to 134.1MPa, 199.4MP and 15.3%, respectively, and the mass-loss rate reduced to be 0.12g⋅m-2⋅h-1. The experimental results in the present research indicated that the grain refinement can effectively improve both the mechanical properties and corrosion resistance of the high-purity Mg.


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