scholarly journals Precipitate Behavior, Mechanical Properties and Corrosion Behavior of an Al-Zn-Mg-Cu Alloy during Non-Isothermal Creep Aging with Axial Tension Stress

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 378 ◽  
Author(s):  
Junhao Zhu ◽  
Bo Jiang ◽  
Danqing Yi ◽  
Haishen Wang ◽  
Guicheng Wu

Theprecipitate behavior, mechanical properties and corrosion behavior of an Al-Zn-Mg-Cu alloy during non-isothermal creep aging were investigated. The results show that diffraction patterns of GPI zones gradually disappear and those of η′ phases are strengthened during the heating stage. More importantly, the size and volume fraction of precipitates increase with aging temperature increasing, which greatly enhances the mechanical properties of the alloy. The hardness and tensile strength of the alloy with H210 aging condition are 165 HV and 564 MPa, respectively. During the cooling stage, in addition to the diffraction pattern of η′ phase, that of GPI zones can be observed again. Furthermore, the size of the precipitates decreases, and the volume fraction reaches a maximum. The hardness and tensile strength of the alloy with C120 aging condition reach 185 HV and 580 MPa, respectively. Furthermore, the characteristics of the grain boundary reveal that the width of precipitation free zones (PFZ) first increases during the heating stage and then decreases during the cooling stage. In the C120 condition, the newly generated secondary precipitates and the coarsening of undissolved precipitates around the grain boundary lead to the further narrowing of PFZ, but the coarse grain boundary precipitates (GBPs) are still not continuously distributed in the grain boundary. Hence, the alloy with C120 condition exhibits the most excellent corrosion resistance.

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2378 ◽  
Author(s):  
Zheng-Xue Zhao ◽  
Zhen-Ming Hua ◽  
Da-Wei Li ◽  
Dong-Song Wei ◽  
Yan Liu ◽  
...  

The microstructure, mechanical properties and corrosion behavior of hot–rolled Mg–xSn–1Zn–0.5Ca (x = 1, 3 and 5 wt.%) alloys were investigated for possible application as biodegradable implants. The hot–rolled Mg–xSn–1Zn–0.5Ca alloys consisted of α-Mg matrix and Mg2Sn phase. The number of the Mg2Sn particles significantly increased and the grains were gradually refined (14.2 ± 1.5, ~10.7 ± 0.7 and ~6.6 ± 1.1 μm), while the recrystallized fraction significantly decreased with the increase in the Sn content, the Mg–1Sn–1Zn–0.5Ca alloy was almost completely recrystallized. Ultimate tensile strength (UTS) and tensile yield strength (TYS) increased slightly, reaching maximum values of 247 MPa and 116 MPa, respectively, for the Mg–5Sn–1Zn–0.5Ca alloy, and the elongation decreased with the increase in the Sn content; the Mg–1Sn–1Zn–0.5Ca alloy showed the highest elongation (15.3%). In addition, immersion tests and electrochemical measurements in Hank’s solution revealed that the corrosion rates of Mg–xSn–1Zn–0.5Ca alloys increased with the increase in the Sn content. A model of the corrosion behavior was discussed for hot–rolled Mg–xSn–1Zn–0.5Ca alloys in Hank’s solution. Among the Mg–xSn–1Zn–0.5Ca (x = 1, 3 and 5 wt.%) alloys, Mg–1Sn–1Zn–0.5Ca alloy exhibits optimal corrosion resistance and appropriate mechanical properties.


2011 ◽  
Vol 378-379 ◽  
pp. 697-700 ◽  
Author(s):  
Jeong Min Kim ◽  
Joon Sik Park ◽  
Ki Tae Kim

The effects of Sn addition on the cast microstructure, mechanical properties, and corrosion behavior were comprehensively investigated. Cast AM60 alloy mainly consisted of primary Mg matrix and Mg17Al12 phase, and the microstructure virtually remained unchanged by the Sn additions up to 2%. Most of added Sn solute atoms were observed to dissolve into the Mg17Al12 phase and only a few fine MgAlSn precipitates were found in the high Sn alloys. Tensile strength at both room and 175oC was rather deteriorated by increasing Sn content, however the creep strength was significantly enhanced by it. Polarization characteristics of cast AM60 based alloys were not remarkably affected by the Sn content.


Author(s):  
Kethavath Kranthi Kumar ◽  
Adepu Kumar ◽  
MVNV Satyanarayana

Material flow has a significant impact on the joint properties and is one of the most challenging aspects to be understood in dissimilar friction stir welding. The present study emphasizes the role of process parameters on material flow, mechanical properties and corrosion behavior of dissimilar friction stir welds of AA5083-AA6061. Microstructural analysis revealed that the onion ring sub-layer width observed at the stir zone was substantially changed by varying process parameters. It was understood that the higher rotational speeds promote better intermixing and enhanced mechanical properties. The notch tensile strength values were in correlation with the intermixing of materials at the stir zone and the highest notch tensile strength value was obtained at 1400 rpm and 60 mm/min. A remarkable degree of material intermixing and fragmentation of intermetallics at higher rotational speeds resulted in better corrosion resistance.


2011 ◽  
Vol 675-677 ◽  
pp. 629-632
Author(s):  
Ai Hui Liu ◽  
Yan Wei Sui ◽  
Bang Sheng Li ◽  
Jing Jie Guo

In this work, the effects of centrifugal radius and mould rotation speed on the tensile strength, yield strength, specific elongation, and microhardness on Al-Cu alloy castings are investigated. The results show that, with increasing the centrifugal radius or mould rotation speed, the mechanical properties increase gradually. With increasing the centrifugal radius, the variation amplitude of mechanical properties of Al-Cu alloys at mould rotation speed 600rpm is greater than that at 300rpm. This is due to the finer microstructure and the strengthened grain boundary and then resulting in the increase of the resistance to dislocation slipping.


Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1036
Author(s):  
Eduardo Colin García ◽  
Alejandro Cruz Ramírez ◽  
Guillermo Reyes Castellanos ◽  
José Federico Chávez Alcalá ◽  
Jaime Téllez Ramírez ◽  
...  

Ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced by one of the largest manufacturers of the ductile iron camshafts in México “ARBOMEX S.A de C.V” by a phenolic urethane no-bake sand mold casting method. During functioning, camshafts are subject to bending and torsional stresses, and the lobe surfaces are highly loaded. Thus, high toughness and wear resistance are essential for this component. In this work, two austempering ductile iron heat treatments were evaluated to increase the mechanical properties of tensile strength, hardness, and toughness of the ductile iron camshaft low alloyed with vanadium. The austempering process was held at 265 and 305 °C and austempering times of 30, 60, 90, and 120 min. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by XRD measurements. The ausferritic matrix was determined in 90 min for both austempering temperatures, having a good agreement with the microstructural and hardness evolution as the austempering time increased. The mechanical properties of tensile strength, hardness, and toughness were evaluated from samples obtained from the camshaft and the standard Keel block. The highest mechanical properties were obtained for the austempering heat treatment of 265 °C for 90 min for the ADI containing 0.3 wt % V. The tensile and yield strength were 1200 and 1051 MPa, respectively, while the hardness and the energy impact values were of 47 HRC and 26 J; these values are in the range expected for an ADI grade 3.


2013 ◽  
Vol 749 ◽  
pp. 407-413
Author(s):  
Hong Xu ◽  
Xin Zhang ◽  
Ji Ping Ren ◽  
Min Peng ◽  
Shi Yang ◽  
...  

The mechanical properties and corrosion performances of the ZL101 alloy modified by the composite master alloy were investigated. The results showed that the master alloy had not only obvious effect of grain refinement, but also a significant role in refining dendrite grain of ZL101 alloy. The grain size decreased dramatically from 150μm to 62μm when the addition of composite master alloy is up to 0.5%(mass fraction) and the temperature is 720 for 30 minutes,. Its tensile strength and elongation increased by 27% and 42% respectively. The grain refinement of ZL101 alloy decreased its corrosion performance. The morphology of Si changed into globular from needle modified by NaF, instead of AlTiB.


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