Fatigue Fracture Behavior of Mg-Zn-Y Alloys

2007 ◽  
Vol 561-565 ◽  
pp. 267-270 ◽  
Author(s):  
Masayuki Tsushida ◽  
Kazuaki Toda ◽  
Hiromoto Kitahara ◽  
Shinji Ando ◽  
Hideki Tonda
Keyword(s):  
Fatigue Fracture ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Thin Sheet ◽  
Testing Machine ◽  
The Other ◽  
Superior Performance ◽  
Fatigue Properties ◽  
Lpso Phase ◽  
Fatigue Fracture Behavior

Recently, Mg-Zn-Y alloys with superior performance, which have a long period stacking order (LPSO) phase, have been developed. Therefore, it is important to understand fundamental fatigue properties in such materials. In this study, the fatigue fracture behavior of the Mg96Zn2Y2 alloy has been investigated with a plain bending testing machine, which was originally developed for thin sheet specimen at room temperature and 523K. One end of the sheet specimen is fixed at a voice coil of the loudspeaker and the other end is set free. A bending mode resonance occurs in the specimen due to forced vibration at the fixed end. To estimate stress amplitude of bending, deflections at the free end of the specimen oscillating at a frequency of about 200~500Hz was measured by a laser displacement gauge. For comparison, AZ31B alloy also has been investigated. S-N curve for the Mg96Zn2Y2 alloy was obtained using a stress ratio of R=-1, and the fatigue strengths were estimated as 200MPa at room temperature and 120MPa at 523K at 106~107 cycles. These values correspond to about 50% of 0.2% proof strengths of the Mg96Zn2Y2 alloy. Two types of fatigue surface were observed in the Mg96Zn2Y2 alloy. One was striation-like-pattern and the other was relatively flat surface. Striation-like-pattern was similar to fatigue surface of AZ31B. Therefore, these two types of fatigue surface correspond to crack passing through α-Mg phase and LPSO phase, respectively. The feature of fracture surface at 523K was almost the same as that at room temperature.

Fatigue Fracture Behavior of Mg-Zn-Y Alloy

2006 ◽  
Vol 326-328 ◽  
pp. 975-978 ◽  
Author(s):  
Shinji Ando ◽  
Kazuaki Toda ◽  
Masayuki Tsushida ◽  
Hideki Tonda ◽  
Yoshihito Kawamura
Keyword(s):  
Fatigue Fracture ◽  
Fracture Behavior ◽  
Thin Sheet ◽  
Testing Machine ◽  
The Other ◽  
Superior Performance ◽  
Fatigue Properties ◽  
Az31b Alloy ◽  
Fixed End ◽  
Fatigue Fracture Behavior

Recently, Mg-Zn-Y alloys with superior performance, which have a long period order (LPO) phase, have been developed. Therefore, it is important to understand fundamental fatigue properties in such materials. In this study, the fatigue fracture behavior of Mg-Zn2-Y2-Zr0.2 alloy has been investigated using a plain fatigue bending testing machine, which was originally developed for thin sheet specimen. One end of the sheet specimen is fixed at a voice coil of the loudspeaker and the other end is set free. A bending mode resonance occurs in the specimen due to forced vibration at the fixed end. To estimate stress amplitude of bending, deflections at the free end of the specimen oscillating at a frequency of about 250~700Hz was measured by a laser displacement gauge. For comparison, AZ31B alloy also has been investigated. S-N curve for the Mg-Zn2-Y2-Zr0.2 alloy was obtained using a stress ratio of R=-1, and the fatigue strength was estimated as about 200MPa at 106~108 cycles. The value corresponds to about 50% of 0.2% proof strength of the alloy. Two types of fatigue surface were observed in the alloy. One is striation like pattern and the other is relatively flat surface. The former is similar to fatigue surface of AZ31B. Therefore, these two types of fatigue surface correspond to crack passing through α-Mg phase and LPO phase, respectively.

Effect of Si Content on the Fatigue Fracture Behavior of Wrought Al-xSi-0.7Mg Alloy

2018 ◽  
Vol 941 ◽  
pp. 1143-1148 ◽  
Author(s):  
Guang Dong Wang ◽  
Ni Tian ◽  
Chong Li ◽  
Gang Zhao ◽  
Liang Zuo
Keyword(s):  
Structural Material ◽  
Fatigue Fracture ◽  
Fracture Behavior ◽  
Low Cost ◽  
Fracture Morphology ◽  
Alloy Sheet ◽  
Fatigue Properties ◽  
Low Thermal Expansion ◽  
Si Content ◽  
Fatigue Fracture Behavior

The wrought Mg-containing high-silicon aluminum alloy has become more attractive as an ideal structural material, because it has moderate strength and the ductility, high wear and corrosion resistance, low thermal expansion coefficient and low cost. However, as structural material, the fatigue properties and the fatigue fracture behavior of it should be paid much more attention to, especially the effect of Si content on the fatigue properties of wrought Mg-containing Al-Si alloy. In this paper, the wrought Al-(1.44%, 4.92%, 6.61%, 8.81% and 12.4%)Si-0.7%Mg alloy were prepared through DCC and homogenization treatment, and then hot-rolled and cold-rolled into 1.3mm sheets. The microstructure and fatigue fracture morphology of Al-(1.44~12.4)Si-0.7Mg-T4 alloy sheet after fatigue test were investigated by LSCM and SEM. The results showed that the size of Si particles in Al-(1.44~12.4)Si-0.7Mg alloy sheets was approximately the same, but the number of Si particles increased as the Si content increased. The size of recrystallization grain in Al-(1.44~12.4)Si-0.7Mg alloy sheets decreased from 47μm to 10μm when Si content increased from 1.44% to 12.4%, which indicates that increasing of Si content can refine the grain of Al-(1.44~12.4)Si-0.7Mg alloy sheets. With the increasing of Si content the propagation area of fatigue fracture surface of Al-(1.44~12.4)Si-0.7Mg alloy sheets in T4 temper became rougher, and crack propagation became more difficult. Moreover, dimples in the fast fracture area became larger in amount, smaller in size and more uniform in distribution.

Inelastic Deformation and Fatigue of Solder Alloys Under Complicated Load Conditions

2006 ◽  
Vol 129 (2) ◽  
pp. 195-204 ◽  
Author(s):  
J. Liang ◽  
N. Dariavach ◽  
P. Callahan ◽  
D. Shangguan
Keyword(s):  
Fatigue Fracture ◽  
Fracture Behavior ◽  
Three Dimensional ◽  
Biaxial Stress ◽  
Life Assessment ◽  
Solder Alloys ◽  
Fundamental Study ◽  
Complex Load ◽  
Fatigue Fracture Behavior ◽  
Load Conditions

Fundamental study of deformation and fatigue fracture behavior of solder alloys under complex load conditions is a key to enabling implementation of sophisticated three-dimensional (3D) time-dependent nonlinear finite-element stress and strain analyses for the life assessment for electronic packages and assemblies. In this study, the rate-dependent deformation and fatigue fracture behavior of Sn3.8Ag0.7CuPb-free alloy and Sn–Pb eutectic alloy was investigated with thin-walled specimens using a biaxial servo-controlled tension–torsion material testing system, with solder alloys subjected to a variety of complex load conditions: pure shearing at strain rates between 6.7×10−7∕s and 1.3×10−1∕s, creep at temperatures ranging from room temperature up to 125°C, and cyclic loading with frequencies of 0.001Hz to 3Hz. Biaxial stress conditions were imposed to investigate the effects of multiaxial stresses on deformation behavior. The effects of frequency and temperature on cyclic deformation and fatigue facture were investigated for lead-free Sn3.8Ag0.7Cu and Sn–Pb eutectic solder. Fractography of fatigue tested samples was also conducted to determine possible fatigue failure mechanisms.

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