Effects of laser peening on plane bending fatigue properties of friction stir welded A6061-T6 alloy

2013 ◽  
pp. 419-423 ◽  
Author(s):  
K. Masaki ◽  
K. Yamashiro ◽  
Y. Sano
Keyword(s):  
Fatigue Properties ◽  
Laser Peening ◽  
Bending Fatigue ◽  
Friction Stir ◽  
Plane Bending

Mechanical Properties of Cast Shape Memory Alloy for Brain Spatula

2011 ◽  
Vol 674 ◽  
pp. 213-218 ◽  
Author(s):  
Hisaaki Tobushi ◽  
K. Kitamura ◽  
Yukiharu Yoshimi ◽  
K. Miyamoto ◽  
K. Mitsui
Keyword(s):  
Fatigue Life ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Power Function ◽  
Tensile Deformation ◽  
Low Cycle Fatigue ◽  
Fatigue Properties ◽  
Bending Fatigue ◽  
Deformation Properties ◽  
Plane Bending

In order to develop a brain spatula or a brain retractor made of a shape memory alloy (SMA), the bending characteristics of the brain spatula of TiNi SMA made by the precision casting were discussed based on the tensile deformation properties of the existing copper and the TiNi rolled-SMA. The fatigue properties of both materials were also investigated by the plane-bending fatigue test. The results obtained can be summarized as follows. (1) The modulus of elasticity and the yield stress for the cast and rolled SMAs are lower than those for the copper. Therefore, the conventional rolled-SMA spatula and the new cast-SMA spatula can be bent easily compared to the existing copper-brain spatula. (2) With respect to the alternating- and pulsating-plane bending fatigue, the fatigue life of both the copper and the SMAs in the region of low-cycle fatigue is expressed by a power function of the maximum bending strain. The fatigue life of the conventional rolled SMA and the new cast SMA is longer than that of the existing copper. The fatigue life of the new cast and rolled SMAs in the pulsating-plane bending is longer than that in the alternating-plane bending. (3) The fatigue life of the rolled-SMA and the cast SMA for alternating- and pulsating-plane bendings can be expressed by the unified relationship with a power function of the dissipated work.

Improvement of Fatigue Properties in a Cast Aluminum Alloy by Roller Burnishing and Friction Stir Processing

2014 ◽  
Vol 891-892 ◽  
pp. 662-667 ◽  
Author(s):  
Yuki Nakamura ◽  
Masaki Nakajima ◽  
Hiroaki Masuda ◽  
Toshifumi Kakiuchi ◽  
Yoshihiko Uematsu
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Friction Stir Processing ◽  
Compressive Residual Stress ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Cast Aluminum Alloy ◽  
Cast Aluminum ◽  
Bending Fatigue ◽  
Friction Stir

Roller burnishing (RB) and friction stir processing (FSP) were applied to a cast aluminum alloy, AC4CH-T6 (equivalent to A356-T6), to improve the fatigue properties. In roller burnished specimens, Vickers hardness was increased until the depth of 60μm compared with that of the as-cast specimens, resulting in work-hardening by RB. The compressive residual stress on the surface of the roller burnished specimens was also increased from 35MPa to 132MPa. In order to investigate the effect of RB on the fatigue properties, rotary bending fatigue tests have been performed using the roller burnished and the as-cast specimens. The roller burnished specimens exhibited higher fatigue strength than the untreated specimens. It is due to the increase in hardness and compressive residual stress by RB. In addition, plane bending fatigue tests have been performed using the friction stir processed and untreated specimens. Fatigue strengths of the friction stir processed specimens were highly improved compared with untreated specimens as the results of the elimination of casting defects by FSP. However, the crack growth rates of the friction stir processed specimens were faster than those of untreated specimens. It is due to the softening of the material by heat input during the FSP.

scholarly journals Effects of Laser Peening on Rotating Bending Fatigue Properties of Ti-6Al-4V Titanium Alloy

2013 ◽  
Vol 62 (5) ◽  
pp. 297-304 ◽  
Author(s):  
Kiyotaka MASAKI ◽  
Youhei KAMESHIMA ◽  
Noriyuki HISAMORI ◽  
Yuji SANO ◽  
Koichi AKITA ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Fatigue Properties ◽  
Laser Peening ◽  
Bending Fatigue ◽  
Rotating Bending Fatigue ◽  
Rotating Bending

scholarly journals Effects of Laser Peening with a Pulse Energy of 1.7 mJ on the Residual Stress and Fatigue Properties of A7075 Aluminum Alloy

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1716
Author(s):  
Yuji Sano ◽  
Kiyotaka Masaki ◽  
Yoshio Mizuta ◽  
Satoshi Tamaki ◽  
Tomonao Hosokai ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Pulse Energy ◽  
Laser Pulses ◽  
Microchip Laser ◽  
Fatigue Properties ◽  
Laser Peening ◽  
Robot Arm ◽  
X Ray Diffraction ◽  
Bending Fatigue ◽  
Laser Peening Without Coating

Laser peening without coating (LPwC) using a palmtop-sized microchip laser has improved the residual stresses (RSs) and fatigue properties of A7075 aluminum alloy. Laser pulses with a wavelength of 1.06 μm and duration of 1.3 ns from a Q-switched Nd:YAG microchip laser were focused onto A7075 aluminum alloy samples covered with water. X-ray diffraction revealed compressive RSs on the surface after irradiation using laser pulses with an energy of 1.7 mJ, spot diameter of 0.3 mm, and density of 100–1600 pulse/mm2. The effects were evident to depths of a few hundred micrometers and the maximum compressive RS was close to the yield strength. Rotation-bending fatigue experiments revealed that LPwC with a pulse energy of 1.7 mJ significantly prolonged the fatigue life and increased the fatigue strength by about 100 MPa with 107 fatigue cycles. The microchip laser used in this study is small enough to fit in the hand or be mounted on a robot arm. The results may lead to the development of tools that extend the service life of various metal parts and structures, especially outdoors where conventional lasers are difficult to apply.

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