Microstructures and Mechanical Properties of ZK60-XHo Wrought Magnesium Alloys

2013 ◽  
Vol 747-748 ◽  
pp. 359-368 ◽  
Author(s):  
Zheng Hua Huang ◽  
Wen Jun Qi ◽  
Jing Xu
Keyword(s):  
Mechanical Property ◽  
Electron Microscope ◽  
Impact Toughness ◽  
Magnesium Alloys ◽  
Optical Microscope ◽  
Second Phase ◽  
Scanning Calorimetry ◽  
Tensile Mechanical Property ◽  
Fine Grain ◽  
Zk60 Alloy

Microstructures and phase compositions of as-cast and extruded ZK60-xHo (x=0~5) alloys were analyzed by X-ray diffraction, differential scanning calorimetry, optical microscope, scanning electron microscope and transmission electron microscope. Meanwhile, tensile mechanical property and impact toughness were tested. The results showed that as-cast microstructure was refined gradually with increasing the Ho content. Mg-Zn-Ho new phase increased gradually, while MgZn2 phase reduced gradually to disappear. Second phase tended to distribute along grain boundary by continuous network. As-cast tensile mechanical property remained almost unchanged and impact toughness value αnK was low (9~17 J/cm2). After extrusion by λ=40/T=593 K, grain size reached the micron level (1~5 μm) and broken second phase distributed dispersedly. Extruded tensile mechanical property was enhanced obviously. Tensile strength σb at ambient temperature increased gradually from 355 MPa for ZK60 alloy to 375 MPa for ZK60-4.77Ho alloy, while elongation δ decreased gradually from 19.5% to 12.5%. σb at 473 K increased gradually from 120 MPa to 169 MPa. Meanwhile, αnK was enhanced to 26~54 J/cm2. Fine grain and few fine dispersed second phase enhanced the tensile mechanical property and impacted toughness of magnesium alloys effectively.

Effect of Solution Treatment on Second Phase Dissolution for an Al-9.2Zn-2.0Mg-1.9Cu Alloy

2020 ◽  
Vol 993 ◽  
pp. 321-326
Author(s):  
Hong Wei Liu ◽  
Kai Wen ◽  
Xi Wu Li ◽  
Zhi Hui Li ◽  
Li Zhen Yan ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Solution Temperature ◽  
Second Phase ◽  
Dsc Analysis ◽  
Scanning Calorimetry ◽  
Phase Dissolution ◽  
Solution Treated ◽  
The Matrix

The second phase dissolution of Al-9.2Zn-2.0Mg-1.9Cu alloy conducted by various temperatures of 2h was researched with the help of optical microscope (OM), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), electrical conductivity and differential scanning calorimetry (DSC) analysis. The results gave rise to the second phase existence of Mg(Zn,Cu,Al)2 and Fe-containing phases in the as-extruded alloy. When the alloy solution treated with a temperature varied from 450°C to 470°C, a small quantity of Mg(Zn,Cu,Al)2 phase still existed in the alloy while its content exhibited a decrement trend with the solution temperature rose. For the alloy solution treated at a temperature of 475°C, Mg(Zn,Cu,Al)2 phase dissolved into the matrix completely while Fe-containing phase still remained. The electrical conductivity of quenched alloy decrease with the solution temperature increase and reached a minimum value at 470°C, and then rose slightly for the solution temperature of 475°C.

The Study on the Precipitation and Mechanical Properties of Steel with Copper

2010 ◽  
Vol 654-656 ◽  
pp. 66-69 ◽  
Author(s):  
Chuang Li ◽  
Xue Min Wang ◽  
Xin Lai He ◽  
Cheng Jia Shang ◽  
Yu He
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Volume Fraction ◽  
Optical Microscope ◽  
Second Phase ◽  
Phase Precipitation ◽  
Precipitation Behavior ◽  
Quenching Temperature ◽  
Bearing Steels ◽  
Transition Electron

The properties and precipitation behavior of Cu-bearing steels have been investigated. The optical microscope and transition electron microscope were employed to study the influence of interrupted cooling and quenching temperature on the precipitation behavior. Also, the properties of samples with different quench processes were tested. The results show that when the steel is interruptedly cooled and quenched from 650-700°C, with the quenching temperature increasing the volume fraction of martensite becomes larger and the hardness becomes higher. When the microstructure is ferrite the second-phase precipitates occurs and they are proved copper-rich particles. However there are no obvious precipitates in martensite. The copper-rich second phase forms by the way of inter-phase precipitation.

scholarly journals Effect of the Zn/Mg Ratio on Microstructures, Mechanical Properties and Corrosion Performances of Al-Zn-Mg Alloys

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3299
Author(s):  
Keda Jiang ◽  
Yanquan Lan ◽  
Qinglin Pan ◽  
Yunlai Deng
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Grain Boundary ◽  
Stress Corrosion ◽  
Intergranular Corrosion ◽  
Optical Microscope ◽  
Mg Alloys ◽  
Sensitivity Index ◽  
Second Phase ◽  
Mechanical Properties And Corrosion

The effect of the Zn/Mg ratio on microstructures, mechanical properties and corrosion performances of Al-Zn-Mg alloys was studied. Microstructures were characterized using the optical microscope (OM), scanning electron microscope (SEM) and transmission electron microscope (TEM). Tensile tests, intergranular corrosion (IGC) and stress corrosion cracking (SCC) tests were conducted to study the properties. Microstructures results indicated that with the decrease of the Zn/Mg ratio, the recrystallization proportion and the fraction of second phase decreased, while the size of η’ (MgZn2) phases in grain interior also significantly decreased. The number density of η’ phases in grain interior increased and grain boundary precipitates developed discontinuous distribution with the decrease of the Zn/Mg ratio. These microstructures contributed to the significant improvement of the strength and corrosion resistance. The tensile strength and yield strength increased by 34.1% and 47.4%, respectively, with the Zn/Mg ratio decreased from 11.4 to 6.1. Calculating results indicated that the enhancement of strength mainly contributed from the solid-solution strengthening, grain-boundary strengthening and precipitation strengthening. The intergranular corrosion degree was greatly relieved and the stress corrosion sensitivity index decreased from 0.031 to 0.007 with the Zn/Mg ratio decreased from 11.4 to 6.1.

Aging Precipitation Evolving Process and its Effects on Mechanical Properties of 0Cr21Ni6Mn9N Austenitic Stainless Steel

2015 ◽  
Vol 816 ◽  
pp. 255-261
Author(s):  
Na Yun Jiang ◽  
Fu Shun Liu
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Electron Microscope ◽  
Austenitic Stainless Steel ◽  
Aging Time ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Precipitation Process ◽  
Second Phase ◽  
Aging Precipitation

The solution treatment (ST) and the the second phase morphology changing duing the aging precipitation process of 0Cr21Ni6Mn9N austenitic stainless steel were investigated using optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM) with EDS and transmission electron microscope (TEM). The results showed that the precipitation phase was Cr2N which initially nucleated along austenitic grain boundaries and then grew towards into the inner grains in strip morphology. Also, with the longer aging time the proportion of Cr2N increased. The mechanical properties of alloys with and without the presence of the precipitation Cr2N were also studied. It was observed that due to the exiting of the precipitation Cr2N, the strength of 2169N stainless steel reduced during a certain range of aging time, and then improved when the aging time reached to 48h, while the elongation decreased thoroughly.

scholarly journals Effect of aging on the microstructures and mechanical properties of AZ80 and ZK60 wrought magnesium alloys

2010 ◽  
Vol 42 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Y.J. Wu ◽  
Z.M. Zhang ◽  
B.C. Li
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Aging Temperature ◽  
Optical Microscope ◽  
Scanning Microscope ◽  
Zk60 Alloy ◽  
Alloy Increase ◽  
Microstructures And Mechanical Properties ◽  
Az80 Alloy ◽  
Peak Value

In this paper, the effects of solution and aging on the microstructures and mechanical properties of AZ80 and ZK60 wrought magnesium alloys are investigated by optical microscope, electronic scanning microscope and mechanical testers. The result shows that both the tensile strength and elongation of AZ80 alloy increase firstly and then decrease with the increasing of the aging temperature, the peak values appear when the aging temperature is 170?C. The hardness of ZK60 alloy increases firstly and then decreases with the increasing of the aging temperature, and the hardness reaches its peak value at 170?C. However, the toughness of the alloy is just the opposite. Moreover, ZK60 alloy has good performances in both impact toughness and other properties at the aging temperature from 140 to 200?C.

Effect of Lower Final Rolling Temperature on Mechanical Properties of V-N Microalloyed Mild Steel

2007 ◽  
Vol 561-565 ◽  
pp. 45-48
Author(s):  
Jian Qing Qing ◽  
Bao Qiao Wu ◽  
Jie Cai Wu ◽  
Yi He
Keyword(s):  
Mechanical Properties ◽  
Mild Steel ◽  
Optical Microscope ◽  
Rolling Temperature ◽  
Second Phase ◽  
Normal Deformation ◽  
Fine Grain ◽  
Final Rolling Temperature ◽  
Second Phase Particles ◽  
Final Rolling

The samples of V-N microalloyed mild steel were obtained in duo mill with the normal deformation rate and the normal rolling temperature except final rolling temperature, which is at 780°C, 730°C and 680°C respectively. The tensile test was carried out and the microstructure was observed with optical microscope. It was found that the mechanical properties improved dramatically compared with normal process, the final rolling temperature is more than 900°C. The main reason is the fine grain size and second phase particles. With the final rolling temperature decreasing, the mechanical property further improves until the final rolling temperature of 700°C.

Study about the Effects of Cryogenic Treatment on the Mechanical Properties of PCrNi3MoVA Steel

2014 ◽  
Vol 541-542 ◽  
pp. 303-306
Author(s):  
Fei Wang ◽  
Yong Cai Chen
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Impact Toughness ◽  
Room Temperature ◽  
Cryogenic Treatment ◽  
Test Results ◽  
Tensile Mechanical Property ◽  
Static Tensile

On the basis of processing the PCrNi3MoVA steel with cryogenic treatment and then experimenting with the static tensile and impulse at room temperature, the effects of cryogenic treatment on macro-mechanical properties of the material is studied. The test results show that tensile mechanical property of PCrNi3MoVA steel can be improved with appropriate number of cryogenic treatment, otherwise can be weakened if the number is inappropriate; at the same time, there is no influence of cryogenic treatment on impact toughness of the material

Effects of Filtration Purification and Solution Treatment on the Microstructure and Mechanical Property of AZ91D Alloy

2016 ◽  
Vol 849 ◽  
pp. 134-141 ◽  
Author(s):  
Wang Han Bo Liu ◽  
Wen Jun Qi ◽  
Zheng Hua Huang
Keyword(s):  
Mechanical Property ◽  
Impact Toughness ◽  
Elevated Temperatures ◽  
Solution Treatment ◽  
Ceramic Foam ◽  
Az91d Alloy ◽  
Tensile Mechanical Property ◽  
Solution Treated ◽  
Before And After ◽  
Microstructure And Mechanical Property

As-cast and solution-treated microstructures of AZ91D alloy before and after the purification by MgO ceramic foam filter (CFF) with different thicknesses at the range from 15 mm to 35 mm were investigated by optical microscopy and scanning electron microscopy. Meanwhile, the tensile mechanical property and impact toughness were tested. The results show that the impurities in the alloy melt could be eliminated by the filtration purification effectively. With increasing the thickness of CFF, the tensile mechanical property and impact toughness first increased significantly, and then decreased slightly. The AZ91D alloy purified by the CFF with the thickness of 20 mm and the porosity of 10 ppi exhibited the best comprehensive mechanical property. The tensile strength σb, elongation δ and impact toughness αnK at ambient temperature reached 205 MPa, 8.5% and 16 J/cm2, with the improving amplitude of 13%, 31% and 46% comparing with the corresponding unpurified value, respectively. At the same time, σb and δ at elevated temperature reached 195 MPa and 31.5%, with the improving amplitude of 9% and 174%, respectively. After the alloy was solution treated, the mechanical property was enhanced further, and the improving amplitude was larger for the alloy by the filtration purification. σb reached 260 MPa and 205 MPa at ambient and elevated temperatures, with the improving amplitude of 32% and 5% comparing with the unpurified value, respectively. αnK reached 27 J/cm2, with the improving amplitude of 69%.

The Effect of Ti-Zr Deoxidation on the Mechanical Properties of High Strength Low Alloy Steels

2010 ◽  
Vol 146-147 ◽  
pp. 1878-1884 ◽  
Author(s):  
Wei Yu Lu ◽  
Ling Dong Meng ◽  
Hong Hong Wang ◽  
Dao Yuan Wang ◽  
Yong Kuan Yao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Impact Toughness ◽  
High Strength ◽  
Optical Microscope ◽  
Low Alloy Steels ◽  
X Ray ◽  
The Matrix ◽  
Alloy Steels ◽  
The Stability

The uniformity of the mechanical properties, especially elongation and impact toughness, were compared between steel A, which was deoxidized with Ti-Zr, and steel B, which was deoxidized with Al. Microstructural observations, energy dispersive X-ray spectroscopy and X-ray diffraction analyses were conducted using an optical microscope, a scanning electron microscope and a transmission electron microscope, respectively. Results showed that sub-micron and nano-sized complex oxides were obtained by the combined deoxidation of Ti-Zr. The stability of the mechanical properties of steel A was better than that of steel B. The elongation and impact toughness of steel A were enhanced relative to those of steel B. This was attributed to spheroidization and the dispersed distribution of MnS inclusions in the matrix of steel A.

scholarly journals Impact Toughness Anisotropy of TA31 Titanium Alloy Cylindrical Shell after Ring Rolling

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4332
Author(s):  
Haiyang Jiang ◽  
Jianyang Zhang ◽  
Bijun Xie ◽  
Zhangxun He ◽  
Hao Zhang ◽  
...  
Keyword(s):  
Cylindrical Shell ◽  
Titanium Alloy ◽  
Electron Microscope ◽  
Impact Toughness ◽  
Scanning Electron Microscope ◽  
Optical Microscope ◽  
Ring Rolling ◽  
Α Phase ◽  
The Impact ◽  
Scanning Electron

The impact toughness of a TA31 titanium alloy cylindrical shell was investigated systemically after ring rolling. The impact toughness of specimens with different notch orientations shows obvious anisotropy. The microstructure of the cylindrical shell and the impact fracture were characterized by an optical microscope and scanning electron microscope. The results show that cracks are easier to propagate in the equiaxed α phase than the elongated α phase. This is because the expanding cracking path in the equiaxed α phase is shorter than that in the elongated α phase, and thereby the cracks are easier to propagate in the equiaxed α phase than the elongated α phase. More specifically, the α phase on the RD-TD plane was obviously isotropic, which makes it easy for the cracks to propagate along α grains in the same direction. However, the α phase on the RD-ND plane has a layered characteristic, and the direction of the α phase varies from layer to layer, thus it requires higher energy for cracks to propagate across this layered α phase. Therefore, the cracks propagating in the same α phase orientation take easier than that in the layered α phase, so it has lower impact toughness.

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