Grain Refinement Mechanism and Improvement of Mechanical Properties of Mg-Gd-Y-Zr Alloy at Elevated Temperature through Ag Addition

Author(s):  
Jian Bao ◽  
Quanan Li ◽  
Xiaoya Chen ◽  
Qian Zhang ◽  
Ziyi Chen
2005 ◽  
Vol 488-489 ◽  
pp. 275-278 ◽  
Author(s):  
Rong Shi Chen ◽  
Jean Jacques Blandin ◽  
Michel Suéry ◽  
En Hou Han

Mechanical properties and microstructure of extruded AZ91(-Ca) alloys have been studied in this paper. The results showed that Ca has no significant effect on reducing grain size of the extruded AZ91 alloy. The ambient temperature tensile tests showed that the ultimate and yield strength of extruded AZ91 alloy decreased by addition of Ca. At elevated temperature, Ca addition improves the yield strength of both AZ91 alloy. The variations in microstructure and mechanical properties of the AZ91 alloy are also discussed in terms of the effects of Ca on grain refinement and formation of constituent phases.


2013 ◽  
Vol 765 ◽  
pp. 521-524 ◽  
Author(s):  
Zhong Yang ◽  
Jian Ping Li ◽  
Yan Rong Wang ◽  
Bi Wei Xiong

The microstructure characteristics and mechanical properties of as-cast and hot extruded Mg-5Gd-4Y-0.5Zn-0.5Zr (GWZ540) alloy were investigated. The results show that coarse the as-cast GWZ540 alloy consisted of α-Mg grain and two second phases, disc-like Mg5(Zn0.2Y0.2Gd0.6) and block-shaped Mg24(Y0.6Gd0.4)5. Hot extrusion resulted in a significant refinement of the α-Mg grains and a uniform distribution of the second phases, but with little effect on the composition and structure of the second phases. It is also shown that GWZ540 alloy exhibits higher UTS and TYS and elongation at both room and elevated temperature than those of WE54 alloy.


2009 ◽  
Vol 610-613 ◽  
pp. 765-770 ◽  
Author(s):  
Zhi Wen Zou ◽  
Shou Mei Xiong

In present work, trace elements Sr and Nd were added into AZ91-1wt%Si alloys. The alloys were cast into a permanent mould and then machined into test bars. The microstructure and mechanical properties at room temperature of the specimens were investigated. Results showed that complicated Chinese script Mg2Si phase decreased in size with the increase of Sr addition. When Sr addition increased to 0.1wt%, the Mg2Si phase was changed from Chinese script shape into uniform polygon shape completely. At the same time, mechanical properties improved due to the morphology modification of the Mg2Si phase. An intermetallic compound containing Mg, Al, Nd and Si was found when Nd was added to the alloy. Remarkable modification on the shape and distribution of the Mg2Si phase was observed because of the intermetallic compound, which leads to a great change in mechanical properties. The grain refinement mechanism of Sr and Nd elements on the Mg2Si phase was discussed.


2008 ◽  
Vol 59 (3) ◽  
pp. 306-311 ◽  
Author(s):  
Jiang Li Ning ◽  
Da Ming Jiang ◽  
Xi Gang Fan ◽  
Zhong Hong Lai ◽  
Qing Chang Meng ◽  
...  

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
A. Saber ◽  
R. Haghayeghi ◽  
H. Najafi ◽  
Peiman Shahbeigi-Roodposhti

The grain refinement of Mg–Al alloy AZ91 via carbon inoculation, including the significant role of Mn in advanced nucleation, was analyzed, and the corresponding mechanical properties and aging behavior were investigated. To this end, various amounts of C were added into the liquid at the desired temperatures. Al8Mn5 particles, which are suitable nucleation sites for α-Mg, were identified as the primary grain refiners. In situ particle formation, along with appropriate wetting and a suitable orientation relationship (OR), facilitated the grain refinement mechanism. Al4C3 particles contributed to heterogeneous nucleation by providing suitable Al8Mn5 nucleation sites. Mn removal resulted in poor grain refinement in the Mg–Al alloy. The Hall–Petch relationship, high-temperature tensile behavior, and aging mechanism of the samples refined by 1 wt % C addition (as the best grain refiner) are discussed and compared with industrial practice.


Sign in / Sign up

Export Citation Format

Share Document