Effect of the Zn/Mg Ratio on Microstructure and Mechanical Properties in Al-Zn-Mg Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 479-482 ◽  
Author(s):  
Masatomo Nishi ◽  
Kenji Matsuda ◽  
Naoya Miura ◽  
Katsumi Watanabe ◽  
Susumu Ikeno ◽  
...  
Keyword(s):  
High Strength ◽  
Hardness Measurement ◽  
Tensile Tests ◽  
Mg Alloys ◽  
Mg Alloy ◽  
Age Hardening ◽  
Peak Hardness ◽  
Number Density ◽  
Peak Aged Condition ◽  
Peak Aged

It is well know that the 7000 series Al-Zn-Mg alloy has good age hardening ability and high strength among commercial aluminum alloys. In this study, hardness measurement, tensile test, SEM and TEM observation have been performed in order to understand the effect of the Zn/Mg ratio on age hardening behaviour in Al-Zn-Mg alloys. It was seen from hardness measurement that the peak hardness increased with increasing amount of Zn and Mg. Tensile tests were performed for the samples of peak aged condition. It was seen that UTS increased with increasing amount of the Zn and Mg. The elongation decreased with increasing the amount of the Zn and Mg. Intregranular fracture was observed in alloys with low amount of Zn and Mg.Transgranular fracture was observed with high amount of Zn and Mg alloy. TEM observation was performed for peak aged samples. The size of precipitates became finer and the number density increased with increasing Zn and Mg contents.T’ Phase and h1 phase were observed in low Zn/Mg alloy. The h’ phase was observed in high Zn/Mg alloy.

Effect of Zn/Mg on Age Hardening Behavior in 7000 System Al Alloys

2014 ◽  
Vol 922 ◽  
pp. 549-552
Author(s):  
Masatomo Nishi ◽  
Naoya Miura ◽  
Katsumi Watanabe ◽  
Susumu Ikeno ◽  
Tomoo Yoshida ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
Tensile Test ◽  
High Strength ◽  
Hardness Measurement ◽  
Age Hardening ◽  
Number Density ◽  
Aged Condition ◽  
Hardening Behavior ◽  
Peak Aged Condition ◽  
Peak Aged

7000 System Al has been known as one of the aluminum alloys with the good age hardening ability and the high strength among commercial aluminum alloys. [1]In this study, hardness measurement, tensile test, SEM observation and TEM observation have been performed in order to understand the effect of Zn/Mg ratio on age hardening behaviour in Al-Zn-Mg alloys . It can be seen from hardness measurement that the alloy containing higher Zn and Mg contents became hard. Tensile test was performed for the samples of peak aged condition. It can been seen that the alloy containing higher Zn and Mg increases the tensile strength of the alloy though decrease of the elongation were observed a typical intergranular fracture. TEM observation was performed for peak aged samples. The size of precipitates became finer and the number density increased with increasing Zn and Mg contents.

TEM Observation of Precipitate Structures in Al-Zn-Mg Alloys with Additions of Cu/Ag

2014 ◽  
Vol 794-796 ◽  
pp. 985-987 ◽  
Author(s):  
Katsumi Watanabe ◽  
Kenji Matsuda ◽  
Susumu Ikeno ◽  
Tomoo Yoshida ◽  
Satoshi Murakami
Keyword(s):  
Mechanical Property ◽  
Aluminum Alloys ◽  
Base Alloy ◽  
High Strength ◽  
Mg Alloy ◽  
Age Hardening ◽  
Number Density ◽  
Maximum Hardness ◽  
Aging Behavior ◽  
Peak Aged

Al-Zn-Mg alloy has been known as one of the aluminum alloys with the good age-hardening ability and the high strength among commercial aluminum alloys. The mechanical property of the limited ductility, however, is required to further improvement. In this work, three alloys, which were added Cu or Ag into the Al-Zn-Mg alloy, were prepared to compare the effect of the additional elements on the aging behavior. The content of Ag and Cu were 0.2at.% and the same as, respectively. Ag or Cu added alloy showed higher maximum hardness than base alloy. The particle shape and rod shape precipitates were observed in all alloys peak-aged at 423K. According to addition of Ag or Cu, the number density of the precipitates increased higher than that of base alloy.

scholarly journals Tem Observation Of Precipitate Structures In Al-Zn-Mg Alloys With Additions Of Cu/Ag

2015 ◽  
Vol 60 (2) ◽  
pp. 977-979 ◽  
Author(s):  
K. Watanabe ◽  
K. Matsuda ◽  
S. Ikeno ◽  
T. Yoshida ◽  
S. Murakami
Keyword(s):  
Mechanical Property ◽  
Aluminum Alloys ◽  
Base Alloy ◽  
High Strength ◽  
Mg Alloy ◽  
Age Hardening ◽  
Number Density ◽  
Maximum Hardness ◽  
Aging Behavior ◽  
Peak Aged

AbstractAl-Zn-Mg alloy has been known as one of the aluminum alloys with the good age-hardening ability and the high strength among commercial aluminum alloys. The mechanical property of the limited ductility, however, is required to further improvement. In this work, three alloys, which were added Cu or Ag into the Al-Zn-Mg alloy, were prepared to compare the effect of the additional elements on the aging behavior. The content of Ag and Cu were 0.2at.% and the same as, respectively. Ag or Cu added alloy showed higher maximum hardness than base alloy. The particle shape and rod shape precipitates were observed in all alloys peak-aged at 423K. According to addition of Ag or Cu, the number density of the precipitates increased higher than that of base alloy.

TEM Observation for Precipitates Structure of Aged Al-Zn-Mg Series Al Alloys Addition of Cu or Ag

2014 ◽  
Vol 922 ◽  
pp. 791-794
Author(s):  
Katsumi Watanabe ◽  
Susumu Ikeno ◽  
Tomoo Yoshida ◽  
Satoshi Murakami ◽  
Kenji Matsuda
Keyword(s):  
Mechanical Property ◽  
Aluminum Alloys ◽  
High Strength ◽  
Al Alloys ◽  
Mg Alloy ◽  
Age Hardening ◽  
Number Density ◽  
Maximum Hardness ◽  
Aging Behavior ◽  
Peak Aged

Al-Zn-Mg alloy has been known as one of the aluminum alloys with the good age-hardening ability and the high strength among commercial aluminum alloys. The mechanical property of the limited ductility, however, is required to further improvement. In this work, three alloys, which were added Cu or Ag into the Al-Zn-Mg alloy, were prepared to compare the effect of the additional elements on the aging behavior. Ag or Cu added alloy showed higher maximum hardness than Ag or Cu free alloy. The η’ phase were observed in all alloys peak-aged at 423K. According to addition of Ag or Cu, the number density of the precipitates increased than Ag or Cu free alloy.

scholarly journals Effect of Ti Addition to Age Hardening Response of Al-10Zn-6MgxTi Alloy Produced by Squeeze Casting

2018 ◽  
Vol 186 ◽  
pp. 02009
Author(s):  
Dwi Ayu Nurcahyaningsih ◽  
Risly Wijanarko ◽  
Irene Angela ◽  
Bondan Tiara Sofyan
Keyword(s):  
Squeeze Casting ◽  
Solution Treatment ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Hardness Measurement ◽  
Impact Testing ◽  
Age Hardening ◽  
Peak Hardness ◽  
7Xxx Alloy ◽  
Ti Addition

This research focused on investigating the effects of Ti addition on the age hardening response of Al 7xxx alloy for Organic Rankine Cycle (ORC) turbine impeller application in power plant generators. Al-10Zn-6Mg wt. % alloys were produced by squeeze casting with 0.02, 0.05, and 0.25 wt. % Ti addition. As-cast samples were homogenized at 400 °C for 4 h. Solution treatment was conducted at 440 °C for 1 h, followed by quenching and ageing at 130 °C for 200 h. Age hardening result was observed using Rockwell B hardness measurement. Other characterizations included impact testing, STA, optical microscopy, and SEM-EDS. Results showed that the addition of Ti in all content variations increased the as-cast hardness due to the diminution of secondary dendrite arm spacing (SDAS) values of the alloy. Ageing at 130 °C strengthened the alloys, however the addition of Ti was not found to affect neither peak hardness nor impact values of the alloy. Identities of second phases formed during solidification were found to be T (Mg32(Al,Zn)49), β (Al8Mg5), and TiAl3, while precipitates produced during ageing were GP Zone, η′, and η (MgZn2).

scholarly journals Development of Precipitation Hardening Parameters for High Strength Alloy AA 7068

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 918
Author(s):  
Julia Osten ◽  
Benjamin Milkereit ◽  
Michael Reich ◽  
Bin Yang ◽  
Armin Springer ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cooling Rate ◽  
Maximum Yield ◽  
High Strength ◽  
Tensile Tests ◽  
Age Hardening ◽  
Scanning Calorimetry ◽  
Cooling Rates ◽  
Critical Cooling Rate ◽  
Kinetics Of

The mechanical properties after age hardening heat treatment and the kinetics of related phase transformations of high strength AlZnMgCu alloy AA 7068 were investigated. The experimental work includes differential scanning calorimetry (DSC), differential fast scanning calorimetry (DFSC), sophisticated differential dilatometry (DIL), scanning electron microscopy (SEM), as well as hardness and tensile tests. For the kinetic analysis of quench induced precipitation by dilatometry new metrological methods and evaluation procedures were established. Using DSC, dissolution behaviour during heating to solution annealing temperature was investigated. These experiments allowed for identification of the appropriate temperature and duration for the solution heat treatment. Continuous cooling experiments in DSC, DFSC, and DIL determined the kinetics of quench induced precipitation. DSC and DIL revealed several overlapping precipitation reactions. The critical cooling rate for a complete supersaturation of the solid solution has been identified to be 600 to 800 K/s. At slightly subcritical cooling rates quench induced precipitation results in a direct hardening effect resulting in a technological critical cooling rate of about 100 K/s, i.e., the hardness after ageing reaches a saturation level for cooling rates faster than 100 K/s. Maximum yield strength of above 600 MPa and tensile strength of up to 650 MPa were attained.

Effect of FSP on Strength and Fracture Toughness of Aluminium Alloy 7000

2018 ◽  
Vol 877 ◽  
pp. 20-25
Author(s):  
P.K. Mandal
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Aluminium Alloy ◽  
Axial Force ◽  
Weight Ratio ◽  
High Strength ◽  
Hardness Measurement ◽  
Traverse Speed ◽  
Age Hardening ◽  
Friction Stir

The cast Al-Zn-Mg 7000 alloy has become one of the most potential structural materials in many engineering fields such as aircraft body, automotive casting due to their high strength to weight ratio, strong age hardening ability, competitive weight savings, attractive mechanical properties and improvement of thermal properties. The cast aluminium alloy has been modified of surface layer through a solid-state technique is called friction stir process (FSP). But basic principle has been followed by friction stir welding (FSW). This process can be used to locally refine microstructures and eliminate casting defects in selected locations, where mechanical properties improvements can enhance component performance and service life. However, some specified process parameters have adopted during experimental works. Those parameters are tool rotation speed (720 rpm), plate traverse speed (80 mm/min), axial force (15 kN), and tool design (i.e., pin height 3.5 mm and pin diameter 3.0 mm), respectively. The main mechanism behind this process likely to axial force and frictional force acting between the tool shoulder and workpiece results in intense heat generation and plastically soften the process material. The specified ratio of rotational speed (720 rpm) to traverse speed (80 mm/min) is considered 9 as low heat input during FSP and its entails low Zn vaporization problem results as higher fracture toughness of aluminium alloy. It is well known that the stirred zone (SZ) consists of refine equiaxed grains produced due to dynamic recrystallization. FSP has been proven to innovatively enhancing of various properties such as formability, hardness and fracture toughness (32.60 MPa√m). The hardness and fracture toughness of double passes AC+FSP aluminium alloy had been investigated by performing Vicker’s hardness measurement and fracture toughness (KIC)(ASTM E-399 standard) tests. Detailed observations with optical microscopy, Vicker’s hardness measurement, SEM, TEM, and DTA analysis have conducted to analyse microstructure and fracture surfaces of double passes FSP aluminium alloy.

scholarly journals The Effects of Thermal Ageing on Properties and Microstructure of Al-6063 Alloy

2016 ◽  
Vol 694 ◽  
pp. 111-115
Author(s):  
C.N. Aiza Jaafar ◽  
I. Zainol ◽  
Mohd Amirul Zalif Mohamad Sapri
Keyword(s):  
Electron Microscope ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Thermal Ageing ◽  
Aged Alloy ◽  
Surface Fracture ◽  
Solution Treated ◽  
Transmission Electron ◽  
Peak Aged Condition ◽  
Peak Aged

The effect of thermal ageing on the properties and microstructure of Al-Mg-Si alloy was investigated. In this work, an extruded Al-6063 alloy samples were used as the main materials. In order to study the effect of thermal ageing, the alloy samples were solution treated at 530 °C and then quenched into water before artificially aged at elevated temperatures between 120 and 250 °C. The ageing response and mechanical properties was monitored by Vickers hardness and tensile tests, respectively. The analysis of surface fracture and microstructure of peak aged alloy were carried out by means of scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. Result shows that the highest hardness value and tensile properties is gained by the alloy that aged at 120 °C. It is found that increasing in hardness and strength values of the alloy are due to precipitates formation during thermal ageing. Fracture analysis on peak-aged condition indicates that the alloy having more ductility after thermal ageing. The result shows that the higher ageing temperature will lead to the higher ductility of the Al-6063 alloy, as a results the alloy’s strength is reduced.

Investigation on the Microstructure and Mechanical Properties of Hot Forged Mg−8Gd−2Y−1Nd−0.3Zn−0.6Zr Alloy

2011 ◽  
Vol 284-286 ◽  
pp. 1598-1602 ◽  
Author(s):  
Xiu Li Hou ◽  
Zhan Yi Cao ◽  
Li Dong Wang ◽  
Li Min Wang
Keyword(s):  
Mechanical Properties ◽  
Large Strain ◽  
Hot Forging ◽  
Tensile Tests ◽  
Age Hardening ◽  
Secondary Phases ◽  
Ageing Treatment ◽  
Size Refinement ◽  
Microstructure And Mechanical Properties ◽  
Peak Aged

The influences of hot forging and ageing treatment on the microstructure and mechanical properties of Mg−8Gd−2Y−1Nd−0.3Zn−0.6Zr (wt.%) alloy have been investigated. The results showed that the grains were significantly refined after hot forging. And the secondary phases in this alloy i.e. Mg5(Gd1-x-yNdxYy) and Mg24(Y1-x-yGdxNdy)5phases were fragmented to small particles due to the large strain during hot forging. Tensile tests revealed that mechanical properties were improved due to grain size refinement. Moreover, the as-forged alloy exhibited remarkable age-hardening response and mechanical properties were further improved by ageing treatment. The ultimate tensile strength, yield strength and elongation of the peak-aged (T5) alloy are 286 MPa, 245 MPa and 5.6 % at room temperature, and 211 MPa, 103 MPa and 19.4 % at 300°C, respectively.

scholarly journals Effects of Mg Addition and Pre-Aging on the Age-Hardening Behavior in Al-Mg-Si

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1046 ◽  
Author(s):  
JaeHwang Kim ◽  
Jiwoo Im ◽  
Minyoung Song ◽  
Insu Kim
Keyword(s):  
Early Stage ◽  
Natural Aging ◽  
Age Hardening ◽  
Number Density ◽  
Hardening Behavior ◽  
Transmission Electron ◽  
Alloy Hardness ◽  
Peak Aged ◽  
Mg Addition ◽  
Cluster 2

Two types of nanoclusters, Cluster (1) and Cluster (2), formed at around room temperature and 100 °C, respectively, affect the age-hardening behavior in Al-Mg-Si alloys. Formation of Cluster (1) during natural aging (NA) is more accelerated in the high-Mg (9M10S) alloy than in the low-Mg (3M10S) alloy. Hardness at the early stage of two-step aging at 170 °C is not increased for the natural aging samples. On the other hand, hardness is directly increased for the pre-aged (PA) specimens. Furthermore, the formation of Cluster (1) during natural aging is suppressed by the formation of Cluster (2) during pre-aging at 100 °C. To understand the effects of heat treatment histories and Mg contents on the microstructure, transmission electron microscopy (TEM) was utilized. All the images were obtained at (001) plane, and peak aged samples with different heat treatments were used. Lower number density of precipitates is confirmed for the natural aging samples compared with the single-aged and pre-aged specimens. A higher number density of precipitates is confirmed for 9M10S in comparison to 3M10S. Hardness results correspond well to the TEM images.

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