Study of Brazeability of SiCP/A356 Composites and Aluminum Alloy Using Semisolid Metal with High Solid Fraction by Stirring

2011 ◽  
Vol 239-242 ◽  
pp. 663-666 ◽  
Author(s):  
Hui Bin Xu ◽  
Quan Xiang Luo ◽  
Jin Ying He ◽  
Bo Fang Zhou ◽  
You Liang Zeng ◽  
...  

The semi-solid brazing process of SiCp/A356 composites and 2024 aluminum alloy using Zn-Al eutectic filler metal at 450 °C has been investigated. The two substrates and Zn-Al filler metal were heated up to the semisolid temperature range of Zn-Al filler metal by a resistance heating plate. In order to mix the filler metal with the base metal of both sides to be a single uniform joint, a stirrer was introduced into the weld seam. After stirring, specimens were sectioned for analysis of macro- and micro-structures along the weld region. The research shows that SiCp/A356 composites and aluminum can be joining by semisolid metal. It can be found that almost half of the oxide film on the surface of the base metal was disrupted and removed through the observation by SEM. The metallurgical bonds formed between the filler metal and the base materials on the interface of oxide had been disrupted. Moreover, the oxide film of surface of aluminum alloy was more thoroughly disrupted and removed than that of surface of composites with existing of SiC particle.

2011 ◽  
Vol 306-307 ◽  
pp. 738-741
Author(s):  
Hui Bin Xu ◽  
Quan Xiang Luo ◽  
Liang Xing ◽  
Bo Fang Zhou ◽  
You Liang Zeng ◽  
...  

This paper explores the brazing process of SiCp/A356 composites and aluminum alloy using semisolid metal. The two substrates were heated up to the semisolid temperature range of Zn-Al filler metal in the joint region by a resistance heating plate. In order to mix the filler metal with the base metal of both sides to be a single uniform joint, a stirrer was introduced into the weld seam. After stirring, specimens were sectioned for analysis of macro- and micro-structures along the weld region. The research shows that SiCp/A356 composites and aluminum can be local joined with semi-solid filler metal. It can be found that part of the oxide film on the interface of the base metal was disrupted and removed through the observation by SEM. The metallurgical bonds can be formed between the filler metal and the base materials. Moreover, the oxide film of surface of aluminum alloy disrupted and removed was easier than that of surface of composites with existing of Sic particle. The joint microstructure with globular α-Al grain enclosed by rich-Zn phase can be obtained after stirring brazing.


2011 ◽  
Vol 189-193 ◽  
pp. 3521-3524 ◽  
Author(s):  
Hui Bin Xu ◽  
Quan Xiang Luo ◽  
Chun Tian Li ◽  
Chang Hua Du

The semi-solid brazing process of SiCp/A356 composites and aluminum alloy was investigated. The two substrates were heated up to the semisolid temperature range of Zn-Al filler metal in the joint region by a resistance heating plate. At this point a stirrer was introduced into the weld seam in order to mix filler metal and the two sides of substrates into a single uniform joint. After stirring, specimens were sectioned for analysis of macro- and micro-structures along the weld region. The research shows that SiCp/A356 composites and aluminum can be successfully joining with semi-solid filler metal. It can be found that most of the oxide film on the surface of the base metal was disrupted and removed through the observation by SEM. The metallurgical bonds formed between the filler metal and the base materials. Moreover, the oxide film of surface of aluminum alloy was more thoroughly disrupted and removed than that of surface of composites with existing of Sic particle. The joint microstructure with globular α-Al grain enclosed by rich-Zn phase can be obtained after stirring brazing.


Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 498 ◽  
Author(s):  
Zhen Yao ◽  
Songbai Xue ◽  
Junxiong Zhang

The effect of trace amounts of GaF3 and Ga2O3 nanoparticles on the wettability and spreadability of CsF-AlF3 flux matched Zn-15Al filler metal were comparatively studied on 6061 aluminum alloy and Q235 low-carbon steel. The experimental results indicate that appropriate amounts of GaF3 and Ga2O3 added into the flux could significantly promote the Zn-15Al filler metal to wet and spread on the surface of 6061 aluminum alloy and Q235 low-carbon steel. The optimum ranges for GaF3 and Ga2O3 were 0.0075–0.01wt.% and 0.009–0.01 wt.%, respectively. Comparative analysis showed that the activity of CsF-AlF3 flux bearing GaF3 was higher than that bearing Ga2O3. The reason for this is that the former flux has a stronger ability to remove oxides of the base metal and reduce the interfacial tension of the molten filler metal and the base metal.


2013 ◽  
Vol 834-836 ◽  
pp. 425-431
Author(s):  
Zhi Ming Du ◽  
Jun Liu ◽  
Jia Hong Niu ◽  
Wang Qi Zhao ◽  
Sen Cong

Microstructure and mechanical properties of 2024 aluminum alloy flange semi-solid thixoforging by changing cavity was investigated. Theoretical calculation and forming test were adopted to study the preparation of flange. It is concluded that the influence factors of forming limit of flanges are radical load P, friction τ and thickness t by theoretical calculation. The results show that it is uniform in the process of forming. Microstructure and mechanical properties of flange have been improved significantly with the increase of the radical load. Way of variable cavity realized the real plastic deformation, which results in high mechanical properties of flange. The flange could obtain fine microstructure with grain sizes of 20~30μm, tensile strength of 433MPa and elongation of 10.1%, with changing amount of 30MPa. The results indicate that the microstructure and mechanical properties could achieve forging requirement and be controlled using changing cavity.


2019 ◽  
Vol 285 ◽  
pp. 271-276
Author(s):  
Hooman Hadian ◽  
M. Haddad-Sabzevar ◽  
Mohammad Mazinani

An internal cooling agent is used in rapid slurry forming (RSF) process to produce a high solid fraction slurry for a short period of time. In the process used in this research, the swarf which is known to be a low enthalpy material was added to the melt as the internal cooling agent. During the process, the swarf started to melt and a semi-solid slurry with a relatively high solid fraction was formed. This slurry was formed by exchanging the enthalpies between the low and high enthalpy materials. A commercial Al-Si-Cu alloy, i.e. AS9U3 Aluminum alloy, was used in this investigation. The microscopic examination showed that the Al-Si eutectic colonies start to melt during the melting process of swarf material resulting in the formation of globular Alpha-Al grains due to the multiplication of secondary dendrites arms. The fracture of dendrites arms and the subsequent spheroidization were suggested to be the origin of non-dendritic globular grains in the final microstructure. The amount of primary globular Alpha-phase was measured by the image analysis software. The results showed that during high pressure die-casting of AS9U3 Aluminum alloy using 4 mm thick samples, around 35 percent solid has been formed at the temperature of 580 oC.


2001 ◽  
Vol I.01.1 (0) ◽  
pp. 365-366
Author(s):  
Shusuke NAKANO ◽  
Toshiji MUKAI ◽  
Masahide KOHZU ◽  
Shigenori TANABE ◽  
Kenji HIGASHI

2011 ◽  
Vol 339 ◽  
pp. 714-717 ◽  
Author(s):  
Siriwan Pannaray ◽  
Sirikul Wisutmethangoon ◽  
Thawatchai Plookphol ◽  
Jessada Wannasin

The aim of this study is to determine the appropriate solution treatment temperature and time of semi solid 2024 Al alloy. Solution heat treatment at 450°C and 480 °C for various times, from 4 hours to 16 hrs, were applied followed by artificial aging at 220 °C for 1 hr. Microstructure of the semi solid cast 2024 aluminum alloy mainly showed globular grain structure which consisted of matrix-α (Al) and grain boundary (GB) - eutectic phases (α+Al2CuMg/Al2Cu). Eutectic GB phases was found to completely dissolved after solution heat treatment at 480°C for 14 hrs while sample solution treated at 450°C for the same time showed the existence of remaining GB phases. Prolonging heat treatment after 14 hrs at both temperatures resulted in the formation of coarse black particles at the grain boundaries which were identified as Mg2Si phases. Therefore the suitable solution treatment of the alloy in this study was at 480°C for 14 hrs.


2011 ◽  
Vol 383-390 ◽  
pp. 2710-2713
Author(s):  
Hui Bin Xu ◽  
Bo Fang Zhou ◽  
Quan Xiang Luo ◽  
You Liang Zeng ◽  
Chang Hua Du

The joining process of SiCp/A356 composites is investigated. The two substrates are heated up to the melt temperature of Zn27Al filler metal by a resistance heating plate. At the time, a stirrer is introduced into the liquid weld seam in order to mix filler metal and two sides of substrates into a single uniform joint. After stirring, specimens are sectioned for the analysis of macro- and micro-structures along the weld region. The research shows that two typical joint interfaces with oxide film and without one were found. So, oxide film on the substrate wasn’t completely disrupted during stirring brazing at 500°C.And, the tensile strength of joint is only 50MPa.


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