306 Influence of Diameter on Tensile Property and Fatigue Life of Industrial Pure Iron Thin Wire

To eliminate the Bi segregation and interfacial embrittlement of the SnBi/Cu joints, we deliberately added some Ag or Zn elements into the Cu substrate. Then, the reliability of the SnBi/Cu–X (X = Ag or Zn) solder joints was evaluated by investigating their interfacial reactions, tensile property, and fatigue life compared with those of the SnBi/Cu and SnAg/Cu joints. The experimental results demonstrate that even after aging for a long time, the addition of the Ag or Zn elements into the Cu substrate can effectively eliminate the interfacial Bi embrittlement of the SnBi/Cu–X joints under tensile or fatigue loadings. Compared with the conventional SnAg/Cu joints, the SnBi/Cu–X joints exhibit higher adhesive strength and comparable fatigue resistance. Finally, the fatigue and fracture mechanisms of the SnBi/Cu–X solder joints were discussed qualitatively. The current findings may pave the new way for the Sn–Bi solder widely used in the electronic interconnection in the future.

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Hydrogen effects on tensile property of pure iron with deformed surface

Materials Science and Engineering A ◽

10.1016/j.msea.2012.09.075 ◽

2013 ◽

Vol 560 ◽

pp. 332-338 ◽

Cited By ~ 14

Author(s):

Shuai Wang ◽

Somei Ohnuki ◽

Naoyuki Hashimoto ◽

Keisuke Chiba

Keyword(s):

Tensile Property ◽

Pure Iron

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The Effect of Fracture Mechanism on Low-Cycle Fatigue Life of Pure Iron at Low Temperature.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A ◽

10.1299/kikaia.63.665 ◽

1997 ◽

Vol 63 (608) ◽

pp. 665-668

Author(s):

Desheng XIA ◽

Jun KOMOTORI ◽

Masao SHIMIZU

Keyword(s):

Fatigue Life ◽

Low Temperature ◽

Fracture Mechanism ◽

Pure Iron ◽

Low Cycle Fatigue ◽

Cycle Fatigue

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On the Fatigue Performance of Nanoparticles Reinforced Iron by Selective Laser Melting

Volume 2: Additive Manufacturing; Materials ◽

10.1115/msec2017-2913 ◽

2017 ◽

Author(s):

Yachao Wang ◽

Jing Shi ◽

Shiqiang Lu ◽

Weihan Xiao

Keyword(s):

Fatigue Life ◽

Selective Laser Melting ◽

Pure Iron ◽

Nano Particles ◽

Second Phase ◽

Strengthening Effect ◽

Cycle Fatigue ◽

Metal Powders ◽

Laser Melting ◽

Effective Measure

Selective laser melting (SLM) is an additive manufacturing process that uses laser beam to melt metal powders and allow the melt to solidify in a layerwise way. SLM has drawn much attention from industry and academia in recent years. Improving the mechanical properties and performance of components fabricated by SLM has been a focused research area. Adding hard second phase particles into metal matrix has been proven an effective measure to strengthen metal material by SLM. In this research, we adopt nano sized TiC particles to reinforce pure iron matrix using the SLM process. The reinforced TiC/iron composite with 0.5 wt.% TiC is successfully fabricated. Tensile tests and fatigue tests are carried out to demonstrate the strengthening effect, and fatigue fracture surfaces are characterized by SEM to understand the fatigue failure mechanism. The obtained experimental data are compared with an existing composite fatigue life prediction model. The results indicate that nano TiC is effective in improving the tensile performance of pure iron, where the ultimate tensile strength (UTS) and yield strength (YS) increase by 17% and 6.3% respectively. TiC nano particles improve the fatigue life principally at lower cycle fatigue regime, while the beneficial effect at high cycle fatigue regime is not significant, mainly due to the large porosity introduced in SLM process. In addition, it is discovered that traditional Ding’s model does not accurately predict the fatigue life of nano TiC/iron composite, and thus more accurate fatigue modeling work is called for.

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Influence of Strain Ratio on Bending Fatigue Life in TiNi Shape Memory Thin Wire

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.340-341.1193 ◽

2007 ◽

Vol 340-341 ◽

pp. 1193-1198 ◽

Cited By ~ 1

Author(s):

Ryosuke Matsui ◽

Hisaaki Tobushi ◽

Yoshiyasu Makino

Keyword(s):

Fatigue Crack ◽

Fatigue Life ◽

Shape Memory ◽

Low Cycle Fatigue ◽

Fatigue Cracks ◽

Strain Ratio ◽

Thin Wire ◽

Bending Fatigue ◽

Rotating Bending ◽

Plane Bending

In this study, we performed the bending fatigue test and investigated the influence of strain ratio on fatigue life in TiNi shape memory thin wire. The pulsating plane bending, alternating plane bending and rotating bending fatigue tests were carried. Additionally, we carried out the observation of the fatigue fracture surface by a scanning electron microscope. The behavior of fatigue crack was investigated. The results obtained are summarized as follows. (1) The martensitic transformation (MT) stress of the superelastic thin wire (SE-NT) is higher than that of the SMA thin wire (SME-NT) and the fatigue life of SE-NT is shorter than that of SME-NT. Maximum bending strain at the fatigue limit is the MT starting strain. (2) The low-cycle fatigue life curve in plane bending for SE-NT is expressed by a power function of maximum strain εmax and the number of cycles to failure Nf. The smaller the strain ratio for the same εmax, the shorter the fatigue life. (3) In both the rotating bending and the plane bending, fatigue cracks nucleate on the surface of the wire and one fatigue crack grows preferentially. The region in which fatigue crack propagated is fan-shaped.

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Microstructures of Laser Processed Fe-Cr Surface Alloys

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100098150 ◽

1981 ◽

Vol 39 ◽

pp. 328-329

Author(s):

P. A. Molian ◽

K. H. Khan ◽

W. E. Wood

Keyword(s):

Cooling Rate ◽

Pure Iron ◽

Continuous Wave ◽

Laser Surface ◽

Material Surface ◽

Constitution Diagram ◽

Incident Power ◽

Surface Alloying ◽

Laser Surface Alloying ◽

Spot Diameter

In recent years, the effects of chromium on the transformation characteristics of pure iron and the structures produced thereby have been extensively studied as a function of cooling rate. In this paper, we present TEM observations made on specimens of Fe-10% Cr and Fe-20% Cr alloys produced through laser surface alloying process with an estimated cooling rate of 8.8 x 104°C/sec. These two chromium levels were selected in order to study their phase transformation characteristics which are dissimilar in the two cases as predicted by the constitution diagram. Pure iron (C<0.01%, Si<0.01%, Mn<0.01%, S=0.003%, P=0.008%) was electrodeposited with chromium to the thicknesses of 40 and 70μm and then vacuum degassed at 400°F to remove the hydrogen formed during electroplating. Laser surface alloying of chromium into the iron substrate was then performed employing a continuous wave CO2 laser operated at an incident power of 1200 watts. The laser beam, defocussed to a spot diameter of 0.25mm, scanned the material surface at a rate of 30mm/sec, (70 ipm).

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