The Effects of Two-Stage Aging on the Microstructure and Mechanical Properties of the New Al-Si-Cu-Mg Alloy

2016 ◽  
Vol 850 ◽  
pp. 581-586 ◽  
Author(s):  
Yan Zheng ◽  
Cong Xu ◽  
Wen Long Xiao ◽  
Hiroshi Yamagata ◽  
Guo Fu Ji ◽  
...  

Two-stage aging treatments were applied to Al-6Si-2Cu-0.5Mg casting alloy, and the influence of aging treatment parameters on the microstructure and mechanical properties was investigated. The experimental results indicated that the microstructure and mechanical properties of Al-6Si-2Cu-0.5Mg alloy were significantly influenced by the aging time and temperature, and the elongation remarkably increased with the aging time increasing before 7 h. In the case of the alloy aged at 200°Cfor 2h, higher hardness and tensile strength were obtained, which may be attributed to precipitation of a large amount of Cu-rich phases. However, the higher elongation was achieved in the alloy under 200°C aging treatment for 5h, while its hardness and tensile strength slightly decreased. It is mainly due to the amount of the Cu-rich phases decrease slightly, but the morphology of the phases evolved from plate-like to bulk-like structure.

2011 ◽  
Vol 462-463 ◽  
pp. 967-971
Author(s):  
Mahamad Noor Wahab ◽  
Mariyam Jameelah Ghazali ◽  
Abdul Razak Daud

Microstructure and mechanical properties of heat treated Al-Si alloy containing up to 10 wt% aluminum nitride (AlN) particles were investigate. In this work high purity AlN powder with different weight percentage of 0, 5, 7 and 10 were calculated as reinforced material to the metal matrix composites. The Al-Si matrix was prepared by a bottom pour stir casting technique. Heat treatment was performed by soaking and followed by an aged treatment. It was found that the AlN particles were scattered randomly distributed in the matrix composite. Ageing induced Si grain transformation into to spheroid shapes while Al dendrites tend to become finer. Ultimate tensile strength (UTS) had improved drastically from to 125MPa to 306MPa for un-aged Al-Si alloy and aged AlN 7 wt%. Fracture morphologies showed a pronounced feature with small dimples, tear ridges and micro neck particularly in the aged samples leading to a higher tensile value and increase in ductility. The presence of AlN particles in the alloys had improved the tensile strength by slowing down the plastic deformation during tensile test.


2011 ◽  
Vol 467-469 ◽  
pp. 257-262
Author(s):  
Guo Fa Mi ◽  
Jin Zhi Zhang ◽  
Hai Yan Wang

Alloys were produced by casting of Cu-Al-Fe-Be and Cu-Al-Fe-Ni aluminum bronzes and aged. The microstructures and mechanical properties were evaluated. The results indicated that solution and aging treatment can significantly improve the plasticity of Cu-Al-Fe-Be and Cu-Al-Fe-Ni, while the strength and hardness remained in the quenched level. Extending the aging time can effectively enhance the mechanical properties of alloys, and the longer the aging time, the higher the electric resistance of alloys. According to the results, the mechanical properties of the Cu-Al-Fe-Be alloy can be improved remarkably by solution treatment for 120 min at 950°C, followed by aging treatment for 120 min at 350°C, and quenched. While the most suitable heat treatment for the Cu-Al-Fe-Ni alloy was solution treatment 120 min at 950°C, followed by aging for 120 min at 450°C, and quenched. The experimental result also suggested that the Cu-Al-Fe-Be alloy possessed higher hardness and tensile strength compared to the Cu-Al-Fe-Ni alloy.


2020 ◽  
Vol 993 ◽  
pp. 575-584
Author(s):  
Bao Liang Shi ◽  
Chao Zhang ◽  
Yao Wen Tang ◽  
Guo Jie Wei ◽  
Yan Li ◽  
...  

The changes of the microstructure and mechanical properties of T23 steel were investigated during high temperature aging at 625 °C up to 3000 h. The results showed that the bainitic lath microstructure first decreased and then totally disappeared with the increase of aging time, the size of the carbides gradually increased and the recovery occurred after aging for 1000 h. The contents of W, Mo elements in the matrix after aging for 3000 h were remarkably decreased by 27.6% and 45% compared with the as-received state. However, no M6C carbides formed in spite of the obvious desolution transformation of W, Mo. Both the yield strength and the tensile strength at room and high temperature were decreased with the increase of aging time at 625 °C, and the tensile strength at high temperature after aging for 3000 h exhibited the largest of decline compared with the as-received state. The main reasons for the decrease of the mechanical properties related to the microstructure variations, such as the size increase of the M23C6 carbides, the dissolution of the bainite lath microstructure and the occurrence of the recovery. Meanwhile, the desolution of W, Mo elements plays an important role in the decrease of the mechanical properties.


2013 ◽  
Vol 310 ◽  
pp. 55-58
Author(s):  
An Ming Li

Quenching and normalizing is selected as the pretreatment process. Microstructure and mechanical properties of subcritical quenched 65Mn steel are investigated when different pretreatment is used. The experimental results show that the content and grain size of the martensite in the 65Mn steel after subcritical quenched are related with pretreatment process. The mechanical properties are determined by the pretreatment process. 65Mn steel exhibits very fine martensite structure when pretreatment process is quenching. The tensile strength and hardness is 65 Mn steel with the pretreatment process of quenching are higher than that of normalizing. The mechanical properties of 65Mn steel can be improved by austenite inverse transformation subcritical quenching. Classifying number in China: TG156


2013 ◽  
Vol 813 ◽  
pp. 427-430
Author(s):  
Se Weon Choi ◽  
Young Chan Kim ◽  
Chang Seog Kang ◽  
Jae Min Jung ◽  
Sung Kil Hong

The effects of Mn and Ca contents on the microstructure and mechanical properties in Al-Mg alloy were investigated. The results showed that mechanical properties of Al-4.5wt.%Mg were increased as Mn content was raised from 0.1 to 0.5wt.%. Thermodynamic analysis and FE-SEM observation showed that Al15(Fe,Mn)3Si2 phase began to form as Mn content exceeded 0.3wt.%. The case of Ca addition, the tensile strength and elongation of Al-4.5wt.%Mg were decreased as Ca content was increased from 0 to 3wt.%. The maximum solubility of Ca for Al is very lower to 0.074wt.%, the most of Ca precipitated in the form of Al2Ca phase which is very brittle and the increase of Ca content was reduced the mechanical properties.


2012 ◽  
Vol 445 ◽  
pp. 237-240
Author(s):  
Bao Hong Zhang ◽  
Zhi Min Zhang

In order to study the effect of deformation extent on microstructure and mechanical properties of as-cast AZ91D magnesium alloy, experiments of direct extrusion were performed at temperature of 420 and different extrusion ratios. The microstructure and mechanical properties of billets and extrudates were measured. Experimental results show that the grain size of as-cast AZ91D magnesium alloy can be dramatically refined by extrusion. Direct extrusion can obviously improve the mechanical properties of as-cast AZ91D magnesium Alloy, comparing with the pre-extruded billet, the tensile strength, yield strength and elongation of extrudate can be improved by at least 83%, 154% and 150% respectively. As the extrusion ratio increases, the tensile strength and yield strength of extrudate will increase at first and then fall.


2013 ◽  
Vol 873 ◽  
pp. 10-18
Author(s):  
Ting Ting Jia ◽  
Guo Shi Chen ◽  
Shuo Zhang ◽  
Ming Wu ◽  
Hao Ran Geng

In this study, hypoeutectic Al-Si casting alloy was investigated to obtain high strength, according to alloying of Cu Mg, refining of Al-5Ti-B master alloy, modifing of Re and T6 heat treatment. The experimental results show that the mechanical properties of the tested alloy reach peak when addition of Al-5Ti-1B alloy is 1.0% after heat treatment, especially the yield strength, correspondingly, microstructure distribution gets to the best state. When Al-5Ti-1B exceeds 1.0%, the mechanical properties descend gradually. The metallic compounds of Mg2Si phase, CuA12 phase and W phase precipitated along the grain boundary and strengthened dispersively can improve mechanical properties of the tested alloys. The yield strength of samples added 0.1% Re (La 50%, Ce 40%) increases slightly, simultaneously, the tensile strength and elongation decreases. After 0.1% Re, the mechanical properties get down.


Author(s):  
Abdullah Hasan Karabacak ◽  
Aykut Çanakçı ◽  
Fatih Erdemir ◽  
Serdar Özkaya ◽  
Müslim Çelebi

Abstract In this study, AA2024-B4C and AA2024-SiC nanocomposites were successfully produced by hot pressing and consolidation methods. The effects of different SiC and B4C contents on the mechanical properties and microstructure of the nanocomposites were investigated. The bending and tensile strength of AA2024-2 wt.% B4C nanocomposites reached up to 1286.7 MPa and 392.9 MPa, respectively. The bending strength of 676.7 MPa and tensile strength of 377.7 MPa were obtained for AA2024-2 wt.% SiC nanocomposites. The addition of the reinforcement can increase the bending strength of the nanocomposites even if porosity increases. Comparing the experimental results showed that B4C reinforced nanocomposites exhibited better mechanical properties than those of SiC reinforced nanocomposites. The type of Al2Cu phase plays a major role in the improvement of mechanical properties of the composites.


2012 ◽  
Vol 562-564 ◽  
pp. 486-489
Author(s):  
Tong Cui ◽  
Ren Guo Guan ◽  
Hai Ming Qin

Mg-Zn-Sr alloy sheet; biomaterial; aging treatment; tensile property Abstract. The microstructures and mechanical properties of a novel biodegradable Mg-Zn-Sr alloy sheet aged at 175°C had been studied. The results indicate that the grain size of the casting alloy Mg-Zn-Sr is changed with the change of content of element Sr, and while it is 1.0 (wt.)%, smaller average grain size is gained which is 38μm, as well as it is increased to 1.5 (wt.)%, the grain size is coarsen obviously. The phase precipitated in the alloy sheet is sufficient and distributed in the uniform style at 175°C for 8h which gained the preferable mechanical properties, which the tensile strength reaches 230MPa, hardness 76.1HV as well as prolongation ratio 12.7%.


2012 ◽  
Vol 217-219 ◽  
pp. 1853-1856
Author(s):  
Rui Ming Su ◽  
Ying Dong Qu ◽  
Run Xia Li ◽  
Rong De Li

The Al-Zn-Mg-Cu (7A04) alloys were prepared by using the method of spraying deposition and the hot extrusion. The effects of two-stage solid solution treatment and single solid solution treatment on the microstructure and mechanical properties of spray deposited 7A04 alloy were investigated. The microstructure and mechanical properties were observed and tested by optical microscopy, SEM, X-ray diffraction and other methods. It is indicated that the two-stage solid solution treatment is better than the single. After the two-stage solid solution, the sizes of recrystallization grains were small and a lot of precipitations were dissolved. And the microstructure was nice by ageing treatment. The tensile strength and elongation of the alloy can respectively reach 740MPa and 5.8 percent by the two-stage solid solution (at 450°C for 1 hour and 475°C for 2 hours) and the aging treatment.


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