Effect of Electroless Ni-P Plating on the Fatigue Strength of Dilute Al-Si Alloys

2014 ◽  
Vol 794-796 ◽  
pp. 290-295
Author(s):  
Norihito Nagata ◽  
Teruto Kanadani ◽  
Minoru Fukuhara ◽  
Makoto Hino ◽  
Koji Murakami
Keyword(s):  
Fatigue Strength ◽  
High Stress ◽  
Aging Treatment ◽  
Hydrogen Gas ◽  
Breaking Elongation ◽  
High Stress Region ◽  
Stress Region ◽  
Electroless Ni ◽  
Clear Increase ◽  
Strength And Ductility

In this study, the effect of electroless Ni-P plating on the fatigue strength of dilute Al-Si alloys was investigated. As results, the following points were clarified. Fatigue strength of the specimen subjected to zincate treatment only after furnace cooling treatment was almost the same as the furnace cooling only. Fatigue strength of the specimen subjected to Ni-P plating after furnace cooling treatment, was reduced overall, except for high-stress region, rather than one of non-processing materials. Fatigue strength of the specimen subjected to Ni-P plating after aging treatment showed a clear increase in comparison with one of non-processing materials. Breaking elongation of the specimen subjected to Ni-P plating after aging treatment showed no significant changes in comparison with one of non-processing materials. On the other hand, breaking elongation of the specimen subjected to Ni-P plating after furnace cooling treatment reduced by half in comparison with one of non-processing materials. Especially, it seems that poor fatigue strength and ductility of plating materials are mainly caused due to interaction between surface precipitates and hydrogen gas.

Effect of Electroless Ni-P Plating on Mechanical Properties of Al-4%Ge Alloy

2016 ◽  
Vol 879 ◽  
pp. 897-902
Author(s):  
Teruto Kanadani ◽  
Norihito Nagata ◽  
Makoto Hino ◽  
Koji Murakami ◽  
Keitaro Horikawa ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fatigue Strength ◽  
Aging Treatment ◽  
Hydrogen Desorption ◽  
Hydrogen Gas ◽  
The Other ◽  
Breaking Elongation ◽  
Other Hand ◽  
Stress Region ◽  
Electroless Ni

In this study, the effect of electroless Ni-P plating on the mechanical properties of Al-4%Ge alloy was investigated. As the results, the following points were clarified. (i) Tensile strength of the specimen subjected to the Ni-P plating after aging treatment or furnace cooling treatment was improved by about 10% in comparison to one of the non-processed specimens. (ii) Breaking elongation of the specimen subjected to the Ni-P plating after aging treatment showed no significant changes in comparison to one of the non-processed specimens. On the other hand, breaking elongation of the specimen subjected to Ni-P plating after a furnace cooling treatment was reduced to 70% in comparison to one of the non-processed specimens. (iii) Fatigue strength of the specimen subjected to the Ni-P plating after a furnace cooling treatment was overall reduced rather than one of non-processed specimens. (iv) Fatigue strength of the specimen subjected to the Ni-P plating after aging treatment was overall reduced, except for the low-stress region, rather than one of the non-processed specimens. (v) In the specimen subjected to Ni-P plating after a furnace cooling treatment or aging treatment, clear hydrogen desorption was recognized. On the other hand, there was only hydrogen desorption from a few of the non-processed specimens. Especially, it is considered that the poor fatigue strength and ductility of the plating materials are mainly due to the interaction between the surface precipitates and hydrogen gas.

Effects of Surface Structure and Hydrogen on the Fatigue Strength of Electroless Nickel-Phosphorus Plated Al-2%Cu Alloy

2018 ◽  
Vol 941 ◽  
pp. 1821-1826
Author(s):  
Teruto Kanadani ◽  
Norihito Nagata ◽  
Keitaro Horikawa ◽  
Keiyu Nakagawa ◽  
Makoto Hino
Keyword(s):  
Fatigue Strength ◽  
Surface Structure ◽  
Aging Treatment ◽  
Electroless Nickel ◽  
Hydrogen Desorption ◽  
Hydrogen Gas ◽  
Alloy Specimen ◽  
Cu Alloy ◽  
Electroless Ni ◽  
Clear Increase

In this study, the effect of the surface structure and hydrogen on the fatigue strength of electroless Ni-P plated Al-2%Cu alloy was investigated. As the results, the following points were clarified. Large precipitates were recognized near the specimen surface of the furnace-cooled Al-Cu alloy, but these were not recognized in the aged Al-Cu alloy. Fatigue strength of the Al-Cu alloy specimen subjected to Ni-P plating after a furnace cooling treatment was overall reduced rather than one of the non-processed specimens. Fatigue strength of the Al-Cu alloy specimen subjected to Ni-P plating after the aging treatment showed a clear increase in comparison to one of non-processed materials. In the Al-2%Cu alloy specimens subjected to Ni-P plating after the furnace cooling treatment or aging treatment, a clear hydrogen desorption was recognized. On the other hand, there was only hydrogen desorption from a few of the non-processed specimens. It is considered that the poor fatigue strength of the plating materials is mainly due to the interaction between the surface precipitates and hydrogen gas.

The Crack Arrest Capability of 9-Percent Ni Steels (ASTM 553, Type 1) LNG Storage Tanks

1991 ◽  
Vol 113 (3) ◽  
pp. 380-384
Author(s):  
P. B. Crosley ◽  
E. J. Ripling
Keyword(s):  
Fracture Toughness ◽  
Residual Stress ◽  
High Stress ◽  
Crack Arrest ◽  
Storage Tanks ◽  
Membrane Stress ◽  
High Stress Region ◽  
Fast Running ◽  
Stress Region

Safety of structures can be assured, even if cracks initiate in localized regions of abnormally low toughness, and/or abnormally high stress (LT/HS), if the materials from which they are fabricated have a high enough crack arrest fracture toughness. When this requirement is met, fast-running cracks that initiate in LT/HS regions arrest when their tip encounters material having normal toughness and stresses. The work described in this paper was carried out to determine the crack arrest capability of LNG storage tanks by determining the longest LT/HS region in which a crack could initiate and still arrest when it leaves this region. The determination consisted of relating a fracture analysis with the measured full-thickness crack arrest fracture toughness of three 9-percent Ni plates which were reported in reference [1]. The calculations used a residual stress pattern, produced by welding, superimposed on a typical membrane stress. The residual stress was selected as an example of a localized high stress region. It was found that tanks built from the poorest of the three tested plates could arrest cracks about 3/4 m long, while tanks built from the two tougher plates could arrest cracks almost 2 m long.

Texture Formation by the Compression Deformation of AA5182 Aluminum Alloy at High Temperatures

2012 ◽  
Vol 715-716 ◽  
pp. 918-923
Author(s):  
Hyeon Mook Jeong ◽  
Kazuto Okayasu ◽  
Hiroshi Fukutomi
Keyword(s):  
Boundary Migration ◽  
High Stress ◽  
Fiber Texture ◽  
Pole Density ◽  
Texture Formation ◽  
High Stress Region ◽  
Stress Region ◽  
Ebsd Technique ◽  
Region 10 ◽  
Main Component

Texture formation of AA5182 for compressive deformation with a range of temperatures from 673K to 823K and strain rates from 5.0×10-4to 5.0×10-2s-1is experimentally investigated by EBSD technique and X-ray diffraction. Fiber textures are observed in all deformation conditions. Stress regions are divided into a low stress region (10~55MPa) and a high stress region (above 55MPa) on the basis of the relationship between stress and grain size. In the low stress region, it is found that the main component of the fiber texture is {001}(compression plane). In this case, the pole density at {001} is increased with increasing temperature at the same stress level. It is concluded that development of {001} component is attributed to grain boundary migration. For the high stress region, the main component of the fiber texture is {011}. It is considered that the formation of {011} component is attributed to the slip deformation by {111}<110> system.

Effect of Boron Addition on Creep Strength in 9Cr-3W-3Co-V-Nb Steels

2007 ◽  
Author(s):  
Nobuyoshi Komai ◽  
Fujimitsu Masuyama
Keyword(s):  
Grain Boundary ◽  
Diffraction Analysis ◽  
Creep Strength ◽  
High Stress ◽  
High Strength Steels ◽  
High Strength ◽  
Strengthening Mechanism ◽  
Boron Addition ◽  
High Stress Region ◽  
Stress Region

Recently, boron is being added to high-strength steels for boilers and turbines in order to raise creep strength. However, there are various points that are not yet fully understood with regard to the creep-strengthening mechanism of boron addition. In order to investigate the influence of boron addition on creep strength, varying the amounts of boron and nitrogen were added in 9Cr-3W-3Co-V-Nb steels tempered two different conditions and investigated. Although creep strengths of all materials converged to become similar in the low-stress region, the materials tempering at 780°C with boron addition which exhibited the lowest strength on the high-stress region is seen to have slightly greater strength on the low-stress region. In analysis of the precipitates and grain boundary of creepruptured material conducted using TEM-EDS and Auger diffraction analysis equipment, the presence of boron could not be detected.

The Effect of Adhesive for Fillet on Stress in Weld-Bonded Joints

2010 ◽  
Vol 450 ◽  
pp. 502-505 ◽  
Author(s):  
Min You ◽  
Jia Ling Yan ◽  
Xiao Ling Zheng ◽  
Nan Feng Xiong ◽  
Ding Feng Zhu
Keyword(s):  
Elastic Modulus ◽  
High Stress ◽  
Bonded Joints ◽  
Longitudinal Stress ◽  
Lap Joint ◽  
Load Bearing Capacity ◽  
High Stress Region ◽  
Single Lap Joint ◽  
Stress Region ◽  
Peak Value

The influence of the fillet with different elastic modulus on the stress distributed in weld-bonded aluminum alloy single lap joint was investigated using elasto-plastic finite element method. The results show that the peak values of the stress along the mid-bondline at the points near the fillet edge were increased as the elastic modulus of the fillet increased. But at points near the both ends of the adherend in over lap zone as well as in the region of the nugget the peak stresses were decreased except longitudinal stress Sx. The peak value of Seqv decreased first, and then it increased again as the elastic modulus in fillet increased. The load-bearing capacity of the whole weld-bonded joints may be improved for the fillet with Adhesive B (825 MPa) for the relative high stress region in nugget was wider and the stress distribution in overlap zone was more uniform.

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