Research on Effect of La on Microstructure in Semi-Solid A356 Alloy

2010 ◽  
Vol 139-141 ◽  
pp. 693-697 ◽  
Author(s):  
Xiao Mei Liu ◽  
Zheng Liu ◽  
Yong Mei Hu
Keyword(s):  
Binary Alloy ◽  
Master Alloy ◽  
Eutectic Reaction ◽  
A356 Alloy ◽  
Size And Morphology ◽  
Semi Solid ◽  
Low Superheat

Semi-solid A356 alloy slurry grain-refined by Al-La master alloy is prepared by low superheat pouring. The effects of La on the morphology and size of primary grain in semi-solid A356 alloy are researched. The results indicate that the semi-solid A356 alloy slurry with particle-like and rosette-like primary grains can be prepared by low superheat pouring. The size and morphology of the primary grain in semi-solid A356 alloy are markedly improved by La. The refining mechanism of La on the morphology and size of the primary grain in semi-solid A356 alloy is delved. The eutectic reaction of Al-La binary alloy provides the effective nuclei for formation of the primary grains in semi-solid A356 alloy.

Effect of Eutectic Reaction Induced by La on Microstructure in Semisolid A356 Alloy

2012 ◽  
Vol 424-425 ◽  
pp. 77-80
Author(s):  
Zheng Liu ◽  
Mei Yan Huang ◽  
Kai Cao ◽  
Hong Biao Xu
Keyword(s):  
Eutectic Reaction ◽  
A356 Alloy ◽  
Primary Phase ◽  
La Addition ◽  
Size And Morphology ◽  
Low Superheat

Semisolid A356 alloy was prepared by low superheat pouring. The effects of La as a kind of refinement on the size and morphology of the primary phase in semisolid A356 alloy were researched. The results indicated that semisolid A356 alloy contained certain La addition with particle-like and rosette-like primary phase could be prepared by low superheat pouring. The size and morphology of primary phase in A356 alloy are markedly improved by the suitable addition of La. The refining mechanism of La on the size and morphology of the primary phase in semisolid A356 alloy were concerned with the eutectic reaction induced by La in the alloy.

Effect of Eutectic Reaction Induced by Pr on Microstructure in Semisolid A356 Alloy

2011 ◽  
Vol 322 ◽  
pp. 361-364
Author(s):  
Zheng Liu ◽  
Xiao Mei Liu ◽  
Yong Mei Hu
Keyword(s):  
Grain Size ◽  
Eutectic Reaction ◽  
A356 Alloy ◽  
Particle Morphology ◽  
Low Superheat

Semisolid A356 alloy, which is grain-refined by Pr, was prepared by low superheat pouring. The effects of grain-refined by Pr on the morphology and the grain size of the primary α-Al in semisolid A356 alloy are researched. The results indicate that semisolid A356 alloy with particle-like and rosette-like primary α-Al can be prepared by low superheat pouring from liquid A356 alloy grain-refined by Pr. The grain size and particle morphology of primary α-Al in A356 alloy are markedly improved by 0.3wt% Pr. The refining mechanism of Pr on the morphology and the grain size of the primary α-Al in semisolid A356 alloy were delved.

A Compound Process Preparing Semi-Solid A356 Alloy Slurry

2010 ◽  
Vol 97-101 ◽  
pp. 1003-1007 ◽  
Author(s):  
Zheng Liu ◽  
Wei Min Mao
Keyword(s):  
Grain Size ◽  
Nucleation Rate ◽  
A356 Alloy ◽  
Electromagnetic Stirring ◽  
Structure Morphology ◽  
Compound Process ◽  
Semi Solid ◽  
Low Superheat

The semi-solid A356 alloy slurry is prepared by compound process, and the effect of the compound process on morphology and size of primary α-Al in A356 alloy is researched. The results indicate that the compound process remarkably affects the morphology and the size of primary α-Al. Primary α-Al with particle-like is distributed uniformly in A356 alloy, and there is no the transient area of change in structure morphology. Compared with the samples prepared by low superheat pouring and slightly electromagnetic stirring, the nucleation rate, morphology and grain size of primary α-Al in A356 alloy are markedly improved by the compound process. The mechanism of refining grain in the compound process is probed.

The Refinement Mechanism of La-Ce Binary Alloy on Primary α Phase in A356 Alloy under Electromagnetic Stirring

2014 ◽  
Vol 217-218 ◽  
pp. 340-346
Author(s):  
Zheng Liu ◽  
Hao Lin Luo ◽  
Qing Chun Chen
Keyword(s):  
Binary Alloy ◽  
Frequency Conversion ◽  
Eutectic Reaction ◽  
A356 Alloy ◽  
The Other ◽  
Electromagnetic Stirring ◽  
Α Phase ◽  
Refinement Mechanism ◽  
Re Elements ◽  
Shape And Size

The refining effects of La-Ce binary alloy on the primary α phase in semisolid A356 alloy prepared by electromagnetically stirred were researched, in which the refinement mechanism of the binary alloy on primary α phase were emphatically approached. The different amount of La-Ce was added into A356 melt, the melt was poured at 620°C and slightly electromagnetically stirred for 15s with an electromagnetic stirrer which was controlled by frequency conversion, then it was isothermally held at 615°C for 10min. The shape and size of primary α phase were measured, and the distribution of La and Ce was researched by SEM and EDS. The results indicated that the RE elements were easy to uniformly distribute around the primary α phase under electromagnetic stirring, and had the obvious refining effect on primary α phase in semisolid A356 alloy, in which there was the finer primary α phase with particle-like in the melt. The refinement mechanism of La-Ce binary alloy under electromagnetic stirring was concerned with the eutectic reaction between RE elements and Al in the melt, in which the α-Al phase resulted from the Al-RE eutectic reaction could serve as the nucleating site of the primary α phase during solidification of A356 alloy. The other reactant from the Al-RE eutectic reaction, Al11Ce3, was also directly used as nucleation of α phase during the solidification.

Influence of Ultrasonic Vibration on Preparation for Semi-Solid A356 Alloy

2011 ◽  
Vol 295-297 ◽  
pp. 1465-1469
Author(s):  
Jia Xuan Wang ◽  
Chun Li ◽  
Li Hong Jiang ◽  
Min Fang
Keyword(s):  
Grain Refinement ◽  
A356 Alloy ◽  
Treatment Temperature ◽  
Primary Phase ◽  
Power Ultrasound ◽  
Average Grain Size ◽  
Experimental Parameters ◽  
Size And Morphology ◽  
Semi Solid ◽  
Ultrasonic Influence

In this paper, semi-solid slurry was prepared by power ultrasonic on flowing A356 melts. A simple device of ultrasonic treatment was made and the method of applying power ultrasound from the top of ingot was adopted. we investigated the influence of the experimental parameters impact on the size and morphology of the primary phase α-Al in A356 slurry, which included the power of the power ultrasound, treatment temperature and the distance between ultrasonic source and the melts ( here refer to from vibration head to the bottom of melt channel in this paper). The regularity of ultrasonic influence on grain refinement and morphology spheroidizing of primary phase α-Al in A356 alloy were obtained. The results show that when the loading power range from 800W to 1000W, the grain refinement effect goes more obviously with the increasing power of ultrasonic, howerer, when the power is up to 1500W, the effect goes worse; and the best primary phase is obtained at 615 oC among the four treatment temperature (645 °C, 630 °C, 615 °C, 600 °C); with the increase of the distance, among the four groups data (7mm, 9mm, 12mm, 15mm), the microstructure of A356 alloy goes more coarse and the segregation is more serious, the average grain size and form factor of the best primary phase α-Al was 29.47um and 0.78, respectively in this study.

Characterization of Globular Microstructure in NMS Processed Aluminum A356 Alloy: The Role of Casting Size

2011 ◽  
Vol 264-265 ◽  
pp. 1868-1877 ◽  
Author(s):  
Farshad Akhlaghi ◽  
Amir H.S. Farhood
Keyword(s):  
A356 Alloy ◽  
Systematic Investigation ◽  
Globular Structure ◽  
Near Net Shape ◽  
Size And Morphology ◽  
Semi Solid ◽  
Aluminum A356 Alloy ◽  
Processing Steps

Semi-solid processing (SSP) technology, due to its ability to provide near-net-shape components with properties far exceeding those of other casting technologies is considered as an alternative for forgings and investment castings. Conventional semi-solid forming, involving the use of heated billets, melt stirring or using cooling slopes require many processing steps and supplementary equipments. This article describes Narrow Melt Stream (NMS), as an alternative process for semi-solid processing of aluminum alloys that eliminates capital cost expenditures, reduces the number of steps required, and hence reduces the costs of making components with a globular structure. However, the applicability of this technique in producing globular structures in the large molds has not been explored. In the present study the results of a systematic investigation on the effects of mold size on the size and morphology of the globular structures formed by NMS processing of Al 356 alloy is reported. For this purpose, five different series of molds were employed. Each series consisted of three molds with identical volumes but different casting moduluses. By using these molds, the effects of casting modulus at constant casting size as well as the effect of casting volume on the size and shape factor of the globular structures in aluminum A356 samples prepared by NMS technique is reported.

Preparation of Semisolid A356 Alloy by a Cooling Slope Processing

2011 ◽  
Vol 675-677 ◽  
pp. 767-770 ◽  
Author(s):  
Jun Xu ◽  
Tong Min Wang ◽  
Zong Ning Chen ◽  
Jing Zhu ◽  
Zhi Qiang Cao ◽  
...  
Keyword(s):  
A356 Alloy ◽  
A356 Aluminum Alloy ◽  
Forming Process ◽  
Pouring Temperature ◽  
Cooling Slope ◽  
Optimum Parameters ◽  
Grain Structures ◽  
Semisolid Forming ◽  
Size And Morphology ◽  
A356 Aluminum

In order to obtain the non-dendritic feedstock for the semisolid forming process, a cooling slope processing was used. In this work, the effects of the angle, length of cooling slope and pouring temperature on the microstructure of A356 aluminum alloy were investigated. It showed that these parameters affect the size and morphology of α-Al phase to some extent. The results indicate that a pouring temperature of 650°C and a cooling slope with 45° in angle and 50 cm in length are the optimum parameters for preparing fine and globular grain structures. To eliminate the solidification shell formed in the surface of cooling slope, a nitride dope was coated on the surface of the cooling slope.

A Control of Microstructure of A356 Alloy by Sequential Semi-Solid Process

2008 ◽  
pp. 569-573
Author(s):  
Sung Chul Lim ◽  
Hai Joong Lee ◽  
Jang Won Kang ◽  
Sang Kil Lee ◽  
Kyung Hoon Kim ◽  
...  
Keyword(s):  
A356 Alloy ◽  
Semi Solid
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