Ultrasonic-assisted brazing of Al–Ti dissimilar alloy by a filler metal with a large semi-solid temperature range

2016 ◽  
Vol 95 ◽  
pp. 296-305 ◽  
Author(s):  
Xiaoguang Chen ◽  
Ruishan Xie ◽  
Zhiwei Lai ◽  
Lei Liu ◽  
Guisheng Zou ◽  
...  
Keyword(s):  
Filler Metal ◽  
Temperature Range ◽  
Ultrasonic Assisted ◽  
Semi Solid ◽  
Solid Temperature

Influence of Electromagnetic Stirring Parameters and Isothermal Extruding on Semi-Solid Forming Performance of ZA27 Alloys

2011 ◽  
Vol 213 ◽  
pp. 414-418
Author(s):  
Xing Wang Duan ◽  
Xiao Hong You ◽  
Ji Hong Tian
Keyword(s):  
Experimental Results ◽  
Electromagnetic Stirring ◽  
Experimental Basis ◽  
Temperature Range ◽  
Parameter Combination ◽  
Cooling Method ◽  
Semi Solid ◽  
Solid Temperature

In this paper, the methods of electromagnetic stirring and isothermal extruding were used to study the semi-solid forming performance of ZA27 alloys. Through summarizing and analyzing the stirring experimental results, the reasonable parameter combination of electromagnetic stirring is that inputting voltage is 180V-200V and stopping stirring temperature is 465°C-475°C and cooling method is quenching. After ZA27 alloys are stirred by using above parameter combination,the spherical microstructures are obtained.Then the billets which were prepared by using above reasonable parameter combination were reheated to semi-solid temperature range for isothermal extruding.The extruding ratio was 4.Because the recrystallization occurs during extruding,the grains of ZA27 alloys become smaller and more uniform after isothermal extruding and per unit extruding force of semi-solid ZA27 alloys decreases by 1/4-1/5 times than that of general casting ZA27 alloys.These results provide a reliable experimental basis for production and application of ZA27 alloys.

Determination of the viscosity of levitated droplets at atmospheric temperatures in an electrodynamic trap

2021 ◽  
Author(s):  
Stephanie Jones ◽  
Mohit Singh ◽  
Denis Duft ◽  
Alexei Kiselev ◽  
Thomas Leisner
Keyword(s):  
Amorphous Solid ◽  
Organic Aerosol ◽  
Photochemical Reactions ◽  
Temperature Range ◽  
Ability To Act ◽  
Levitated Droplets ◽  
Semi Solid ◽  
Future Work ◽  
The Impact

<p>The impact of atmospheric aerosol on the climate remains poorly understood. Organic aerosol makes up a significant fraction of total aerosol and is prevalent throughout the atmosphere. It can exist as a liquid, semi-solid or amorphous solid. The viscosity of organic aerosol will have an impact on transformations that organic aerosol will undergo during its lifetime such as evaporation and growth, heterogeneous and photochemical reactions as well as the ability to act as an ice nucleating particle.  Therefore, it is of key importance to be able to determine aerosol viscosity over a range of atmospherically relevant conditions in order to better understand the impact of organic aerosol on the climate.</p> <p>Here we report proof of concept viscosity measurements of water droplets levitated in an electrodynamic balance over a range of temperatures. Charged droplets are levitated in a temperature and relative humidity-controlled environment allowing properties over a temperature range of 300 to 220 K to be studied. As the droplets evaporate they reach a point where Coulomb instabilities are induced resulting in droplet oscillations. The relaxation of these oscillations can then be probed to determine the droplet viscosity. Future work will involve determination of the viscosity of different types of organic aerosol over a broad temperature range.</p>

Short-Term Oxidation Behavior, Microstructure Evolution and Compression Behavior of Nickel-Based Superalloy GH4037 in Solid and Semi-Solid States

2022 ◽  
Vol 327 ◽  
pp. 11-25
Author(s):  
Guan Fei Xiao ◽  
Ju Fu Jiang ◽  
Ying Wang ◽  
Ying Zhe Liu ◽  
Ying Zhang ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Deformation Mechanism ◽  
Deformation Zone ◽  
Solid Particles ◽  
Isothermal Treatment ◽  
Short Term ◽  
Solid States ◽  
Nickel Based Superalloy ◽  
Semi Solid ◽  
Solid Temperature

Semi-solid processing combines the advantages of traditional forging and casting methods, so it has received much attention recently. However, the research on semi-solid behaviors of Nickel-based superalloys has been rarely reported. In order to investigate the behaviors of Nickel-based superalloy at solid and semi-solid states, oxidation experiments, isothermal treatment experiments and deformation experiments of GH4037 alloy were studied. Short-term oxidation experiments of GH4037 alloy were carried out at a solid temperature (1200 °C) and a semi-solid temperature (1360 °C). The results indicated that the oxides formed at 1200 °C were mainly composed of TiO2, Cr2O3 and a small amount of spinels NiCr2O4, while the oxides formed at 1360 °C consisted of the spinels of NiCr2O4, NiWO4 and NiMoO4 besides TiO2 and Cr2O3. Microstructure evolution of GH4037 alloy after semi-solid isothermal treatment at 1370 °C and 1380 °C was studied. The results indicated that semi-solid microstructures consisted of equiaxed solid grains and liquid phases. The average grains size and shape factor of solid grains were affected by melting mechanism and grain growth mechanism. Compression behaviors of GH4037 alloy after compressed at 1200 °C and 1360 °C were investigated. The results indicated that the flow stress of 1360 °C decreased significantly compared to that of 1200 °C. The deformation zones in the specimens were divided into three parts: the difficult deformation zone, the large deformation zone, and the free deformation zone. At 1200 °C, the deformation mechanism was plastic deformation mechanism. At 1360 °C, sliding between solid particles (SS), liquid flow (LF), flow of liquid incorporating solid particles (FLS), plastic deformation of solid particles (PDS) coexisted in the compression specimen.

scholarly journals Cavitation at filler metal/substrate interface during ultrasonic-assisted soldering. Part I: Cavitation characteristics

2018 ◽  
Vol 49 ◽  
pp. 249-259 ◽  
Author(s):  
Zhengwei Li ◽  
Zhiwu Xu ◽  
Lin Ma ◽  
Sheng Wang ◽  
Xuesong Liu ◽  
...  
Keyword(s):  
Filler Metal ◽  
Metal Substrate ◽  
Substrate Interface ◽  
Ultrasonic Assisted

Ultrasonic-assisted brazing of SiC ceramic to Ti–6Al–4V alloy using a novel AlSnSiZnMg filler metal

2013 ◽  
Vol 105 ◽  
pp. 120-123 ◽  
Author(s):  
Xiaoguang Chen ◽  
Jiuchun Yan ◽  
Sichao Ren ◽  
Jinghui Wei ◽  
Qian Wang
Keyword(s):  
Filler Metal ◽  
Sic Ceramic ◽  
Ultrasonic Assisted

Rheo-Extrusion of A7075 Aluminium Alloy Utilizing Semi-Solid Slurry Manufactured by Simple Method

2006 ◽  
Vol 519-521 ◽  
pp. 1847-1852 ◽  
Author(s):  
Ryotaro Nagata ◽  
Yasuhiro Uetani ◽  
Hidetoshi Takagi ◽  
Kenji Matsuda ◽  
Susumu Ikeno
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
Simple Method ◽  
Grain Sizes ◽  
Thin Tube ◽  
Feed Stock ◽  
Cooling Tube ◽  
Ram Speed ◽  
Semi Solid ◽  
Solid Temperature

In order to extrude A7075 aluminum alloy soundly from melt without using feed stock billet, rheo-extrusion was tried by utilizing semi-solid slurry with fine solid granules made by employing cooling tube. When the melt moving down inside thin tube was adequately cooled in different ways and introduced into an extrusion container kept at semi-solid temperature of 873K, structure of solidified slurries were granular and mean grain sizes of about 60 to 120μm could be obtained. Subsequently, these slurries were extruded to round bars at various extrusion ratios (28 to 64) and press ram speed of 10mm/s, just after cooling to 833K. The newly developed slurries could easily be extruded to bars with smooth surfaces at lower forces. Although every tensile strength of extruded bars were lower than that of hot-extruded one, there was a tendency that finer the solid granules in slurry, higher the tensile strength of extruded bar.

Semi-Solid Stirring Brazing of SiCp/A356 Composites and Aluminum Alloy in Air

2011 ◽  
Vol 189-193 ◽  
pp. 3521-3524 ◽  
Author(s):  
Hui Bin Xu ◽  
Quan Xiang Luo ◽  
Chun Tian Li ◽  
Chang Hua Du
Keyword(s):  
Aluminum Alloy ◽  
Oxide Film ◽  
Weld Seam ◽  
Filler Metal ◽  
Joint Region ◽  
Base Materials ◽  
Semi Solid ◽  
Micro Structures ◽  
Two Sides ◽  
Sic Particle

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.

scholarly journals Compressive Properties of A2024 Alloy Foam Fabricated through a Melt Route and a Semi-Solid Route

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 153 ◽  
Author(s):  
Takashi Kuwahara ◽  
Taro Osaka ◽  
Mizuki Saito ◽  
Shinsuke Suzuki
Keyword(s):  
Grain Size ◽  
Absorption Efficiency ◽  
S Phase ◽  
Compressive Properties ◽  
Alloying Element ◽  
Plateau Stress ◽  
Energy Absorption Efficiency ◽  
Semi Solid ◽  
Primary Crystals ◽  
Solid Temperature

A2024 alloy foams were fabricated by two methods. In the first method, the melt was thickened by Mg, which acts as an alloying element (melt route). In the second method, the melt was thickened by using primary crystals at a semi-solid temperature with a solid fraction of 20% (semi-solid route). A2024 alloy foams fabricated through the semi-solid route had coarse and uneven pores. This led to slightly brittle fracture of the foams, which resulted in larger energy absorption efficiency than that of the foams fabricated through the melt route. Moreover, A2024 alloy foams fabricated through the semi-solid route had a coarser grain size because of the coarse primary crystals. However, by preventing the decrease in the alloying element Mg, the θ/θ’ phase was suppressed. Additionally, by preventing the precipitation of the S′ phase, the amount of Guinier-Preston-Bagaryatsky (GPB) zone increased. This resulted in a larger plateau stress.

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