Influence of Extrusion Ratio on Microstructures and Properties of Cu-17Ni-3Al-X Alloy

2013 ◽  
Vol 477-478 ◽  
pp. 1307-1315 ◽  
Author(s):  
Yuan Hui Weng ◽  
Yuan Xuan Liu ◽  
Tan Wei ◽  
Wei Wen Zhang ◽  
Zong Qiang Luo

The microstructures and mechanical properties of the Cu-17Ni-3Al-X alloy hot-extruded at different extrusion ratios were investigated by tensile and hardness testing, optical microscope (OM) and scanning electronic microscope.The results show that the dynamic re-crystallization occurs when the extrusion ratio λ increases from 8 to 25. The grain size and the second phases of the extruded alloys are obviously finer than that of the as-cast alloy. The mechanical properties of the extruded alloys are improved remarkably. The alloy with the λ of 25 obtained the tensile strength of 1025MPa, Brinell Hardness of 312HB and elongation of 10.0% which is 35%, 14% and 355%, respectively, higher than that of the as-cast alloy.

2013 ◽  
Vol 749 ◽  
pp. 105-111
Author(s):  
Wei Yan ◽  
Yuan Hui Weng ◽  
Zong Qiang Luo ◽  
Wei Wen Zhang

The microstructures and mechanical properties of the Cu-17Ni-3Al-X alloy extruded at different temperatures were investigated by hardness and tensile tests, optical microscope and scanning electronic microscope. The experimental results showed that dynamic re-crystallization occured during the hot extrusion at 1000 . The grain size of the extruded alloy was significantly refined and the mechanical properties increased remarkably compared to the as-cast alloy. The alloy extruded at 1075 exhibited good mechanical properties with tensile strength of 994 MPa, Brinell hardness of 296 and elongation of 8.0%, which are 30%, 9% and 285% higher than that of the as-cast alloy.


2017 ◽  
Vol 898 ◽  
pp. 124-130 ◽  
Author(s):  
Shu Min Xu ◽  
Xin Ying Teng ◽  
Xing Jing Ge ◽  
Jin Yang Zhang

In this paper, the microstructure and mechanical properties of the as-cast and heat treatment of Mg-Zn-Nd alloy was investigated. The alloy was manufactured by a conventional casting method, and then subjected to a heat treatment. The results showed that the microstructure of as-cast alloy was comprised of α-Mg matrix and Mg12Nd phase. With increase of Nd content, the grain size gradually decreased from 25.38 μm to 9.82 μm. The ultimate tensile strength and elongation at room temperature of the Mg94Zn2Nd4 alloy can be reached to 219.63 MPa and 5.31%. After heat treatment, part of the second phase dissolved into the magnesium matrix and the grain size became a little larger than that of the as-cast. The ultimate tensile strength was declined by about 2.5%, and the elongation was increased to 5.47%.


2011 ◽  
Vol 704-705 ◽  
pp. 1095-1099
Author(s):  
Peng Liu ◽  
Hao Ran Geng ◽  
Zhen Qing Wang ◽  
Jian Rong Zhu ◽  
Fu Sen Pan ◽  
...  

Effects of AlN addition on the microstructure and mechanical properties of as-cast Mg-Al-Zn magnesium alloy were investigated using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and tensile testing. Five different samples were made with different amounts of AlN(0wt%, 0.12wt%, 0.30wt%, 0.48wt%, 0. 60wt%). The results show that the phases of as-cast alloy are composed of α-Mg,β-Mg17Al12. The addition of AlN suppressed the precipitation of the β-phase. And, with the increase of AlN content, the microstructure of β-phase was changed from the reticulum to fine grains. When AlN content was up to 0.48wt% in the alloy, the β-phase became most uniform distribution. After adding 0.3wt% AlN to Al-Mg-Zn alloy, the average alloy grain size reduced from 102μm to 35μm ,the tensile strength of alloy was the highest. The average tensile strength increased from 139MPa to 169.91MPa, the hardness increased from 77.7HB to 98.4HB, but the elongation changes indistinctively. However, when more amount of AlN was added, the average alloy grain size did not reduce sequentially and increased to 50μm by adding 0.6wt% AlN and the β-phase became a little more. Keywords: Al-Mg-Zn alloy; AlN; β-Mg17Al12; Tensile strength


2011 ◽  
Vol 197-198 ◽  
pp. 655-661
Author(s):  
Ze Bin Yang ◽  
Ding Yi Zhu ◽  
Wei Fa Yi ◽  
Shu Mei Lin ◽  
Cheng Mei Du

We investigate the influence of grain size on mechanical properties in a Fe-9Ni-12Mn-2.5Si-1.0C TWIP steel by unidirectional tensile. Meanwhile the microstructures of the TWIP steel were observed and analyzed by optical microscope (OM) and transmission electron microscope (TEM). The experimental results show that the TWIP steel’s yield strength and tensile strength decrease with the increasing of grain size, whereas the plasticity increases with it. When the average grain size reaches to 27μm, the tensile strength is 1080MPa, the elongation percentage is 77%, and the strength-plasticity product achieves the 83160MPa•%. Steel’s strain hardening rate can be changed from three-stage to four-stage with the increasing of grain sizes, the areas of strain hardening by twin deformation mechanism are expanded. Through the microstructure observation we found that, coarse-grained TWIP steel conducts to twinning formation, the high density twins can increase the alloy’s ductility by splitting the grain.


2012 ◽  
Vol 472-475 ◽  
pp. 707-711
Author(s):  
Guan Lu ◽  
Ya Qin Yang ◽  
Bao Cheng Li ◽  
Zhi Min Zhang

In this paper, the effects of hot extrusion and T5、T6 heat treatment on the microstructures and mechanical properties of ZK60 magnesium alloys are investigated by optical microscope, electronic scanning microscope and mechanical testers. The result shows that both the tensile strength and the elongation of the ZK60 alloy extruded at 380°Care much higher than that of the as-cast alloys, as there are much granular second phases precipitated during the extrusion. The tensile strength of the extruded and T5 treated alloy increases while the elongation decreases faster than that of the extruded alloy. The strengthening effect of the T6 treatment is inferior to that of the T5 treatment. The tensile fracture of the as-cast alloy is brittle fractured while that of the extruded and T5 treated alloy is ductile fractured with lots of deep and even dimples.


2012 ◽  
Vol 476-478 ◽  
pp. 29-33
Author(s):  
Shao Ding Sheng ◽  
Hong Ge Yan

AZ91 alloy powder was prepared by two-roller quenching equipment. The powders were consolidated and extruded into bar. The microstructures of the powders and bars were observed by optical microscope (OM), XRD, HRTEM and SEM. The results suggested that the grain size of the powder were equiaxed with the sizes of about 1~5μm. The as-extruded alloy bars retain equiaxed grains with a large number of precipitated phases, β-Al12Mg17 and AlMg2Zn. The alloy exhibited excellent mechanical properties, the ultimate and yield tensile strength were 383.2MPa and 275.1MPa respectively. The shape of the precipitated phase was approximately globular with the size of about 50~200nm.


2018 ◽  
Vol 202 ◽  
pp. 01001
Author(s):  
R. Ahmad ◽  
A.M.M. Elaswad ◽  
M. Z. Hamzah ◽  
N. R. Shahizan

The thermal parameters of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr cast alloy with 0.25 wt.% of erbium (Er) were evaluated by the computer-aided cooling curve thermal analysis(CA CCTA), whereas the microstructure analysis was investigated by the optical microscope and scanning electron microscopy. Results from the cooling curve and microstructure analysis showed that Er altered the grain size of the alloys. In addition, the grain size was reduced by approximately 19.6% with the addition of Er. Scanning electron microscopy results showed that Er formed an Mg-Zn-Nd-Er phase which distributed along the grain boundaries. Furthermore, the mechanical properties were investigated by hardness and tensile tests with Er addition. The addition of 0.25 wt.% of Er significantly improved the ultimate tensile strength and yield strength. In addition, the hardness value of Mg-2.8Nd-1.5Gd-0.5Zn-0.5Zr increased by 13.9% with Er addition.


2013 ◽  
Vol 668 ◽  
pp. 823-829 ◽  
Author(s):  
Xiu Qing Zhang ◽  
Ge Chen ◽  
Yang Wang ◽  
Min Yu Han

Homogenized magnesium alloy Mg-6Zn-Si-0.25Ca has been hot-extruded and then aging treated for improving the magnesium alloy plastic deformation ability and promoting applications of magnesium alloys. In the hot extrusion process, the influences of extrusion parameters for microstructures and mechanical properties of Mg-6Zn-Si-0.25Ca magnesium alloy were investigated. The results show that dynamic recrystallization occurred during hot extrusion. Compared with as-cast alloy, the grains are fined remarkably, and the mechanical properties are enhanced obviously. Twin crystals appeared in grains after hot extrusion, with the extrusion temperature rising, twin crystal structures has been reduced. Aging further increased the mechanical properties of the estruded alloy. The ultimate tensile strength of Mg-6Zn-Si-0.25Ca alloy is about 385 MPa and the elongation is about 11% when extruded at 320°C(extrusion ratio is 10) and aged at 190°C for 8h.


2005 ◽  
Vol 488-489 ◽  
pp. 385-388
Author(s):  
Qiang Li ◽  
Qu Dong Wang ◽  
Xiao Qing Zeng ◽  
Wen Jiang Ding ◽  
Quanbo Tang ◽  
...  

Nd, Y and Ca containing Mg-Zn-Zr alloys are produced by electromagnetic direct-chilling casting process, and extruded at a temperature of 643K with two extrusion ratios of 38:1 and 22:1, respectively. The grain size is markedly reduced from 80µm in as-cast alloy to 2~5µm in as-extruded alloy due to dynamic recrystallization, and lamellar eutectics at grain boundaries in as-cast alloy are broken up and fine precipitates in the matrix come forth during hot extrusions. Mechanical properties of the alloys are measured by tensile test from room temperature to 523K. Nd, Y and Ca are favorable to the strength of the hot-extruded alloy, especially the elevated-temperature strength, which is above 200MPa in ultimate tensile strength at 523K.


2017 ◽  
Vol 898 ◽  
pp. 191-198
Author(s):  
Yu Peng Xu ◽  
Ze Sheng Ji

The Al-Cu-Mg-Ag-Ce-Er alloy wires with different extrusion ratio (λ=12, 25, 50, 100) were produced by hot extrusion at 450oC. The effects of extrusion ratio on the microstructures, tensile strength and elongation of Al-Cu-Mg-Ag-Ce-Er alloy wires were researched by means of OM, SEM, TEM and mechanical test.The results show that with the extrusion ratio increasing, the average grain size decreased from 83μm to 42μm, the Al2Cu, Al8Cu4Ce and Al8Cu4Er phases was broken gradually, and the homogeneousdistribution about these second-phases in the alloy wires increased. The tensile strength increased from 366MPa to 459MPa with extrusion ratio, and the elongation initially decreased and then increased with the increase of extrusion ratio. Dynamic recrystallization for Al-Cu-Mg-Ag-Ce-Er alloy occurred at different extrusion ratios. Withincreasing of extrusion ratio, the main nucleation mechanism of dynamic recrystallization changed from the sub-grain coalescence at lower extrusion ratioto the acceleration of second-phases for nucleation at higher extrusion ratio.


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