Fatigue Characteristics of Nonferrous Bolts

2013 ◽  
Vol 577-578 ◽  
pp. 417-420 ◽  
Author(s):  
Shinji Hashimura ◽  
Tetsuya Torii ◽  
Yukio Miyashita ◽  
Shigeru Yamanaka ◽  
Genki Hibi
Keyword(s):  
Aluminum Alloy ◽  
Magnesium Alloy ◽  
Fatigue Tests ◽  
Bolted Joint ◽  
Fatigue Characteristics ◽  
Axial Fatigue

Fatigue characteristics of bolted joint tightened with a steel bolt have been discussed extensively. However the fatigue characteristics of bolted joint tightened with a nonferrous bolt have not been sufficiently discussed. In this study, two types of fatigue tests, axial fatigue tests and transverse fatigue tests, for nonferrous bolts were conducted. The nonferrous bolts used in this study made of AZ31 and AZX912 magnesium alloy and A5056 aluminum alloy. The results of both fatigue tests showed that the fatigue limits of the A5056 bolt were the highest of all. The fatigue limits of two kinds of the magnesium alloy bolts were almost the same in both fatigue tests. However the ration of the axial fatigue limits to the transverse fatigue limits were different according to the bolt materials.

Fatigue Characteristics of Bolted Joint under Transverse Vibration ~Influence of Bolt Tightening Conditions on Transverse Fatigue Strength~

2010 ◽  
Vol 452-453 ◽  
pp. 609-612
Author(s):  
Shinji Hashimura ◽  
YU Kurakake ◽  
Shinichi Umeno
Keyword(s):  
Fatigue Strength ◽  
Fatigue Limit ◽  
Transverse Vibration ◽  
Bending Moment ◽  
Fatigue Tests ◽  
Bolted Joint ◽  
The Real ◽  
Thread Length ◽  
Fatigue Characteristics

Fatigue tests under transverse vibration were performed for three separate tightening conditions to investigate the grip length and the engaging thread length in this study. The relationships between the apparent fatigue limit (the highest amplitude of transverse vibration force which can be applied to the bolted joint without generating fatigue) and the real fatigue limit of bolt material also were investigated. Results showed that apparent transverse fatigue limit decreased if the grip length was long. And relationships of the apparent fatigue limit and the real fatigue limit were different in each tightening conditions depending on the bending moment at the root of the first thread.

Bolt Load Loss Behavior of Magnesium Alloy AZ91D Bolted Joints Clamped with Aluminum Alloy A5056 Bolt

2013 ◽  
Vol 313-314 ◽  
pp. 135-139
Author(s):  
Supamard Sujatanond ◽  
Yukio Miyashita ◽  
Shinji Hashimura ◽  
Yoshiharu Mutoh ◽  
Yuichi Otsuka
Keyword(s):  
Plastic Deformation ◽  
Thermal Expansion ◽  
Aluminum Alloy ◽  
Magnesium Alloy ◽  
Friction Condition ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Az91d Magnesium Alloy ◽  
Alloy Az91d ◽  
Scm435 Steel

The bolt load loss behavior of AZ91D magnesium alloy bolted joints with a conventional SCM435 steel bolt and an A5056 aluminum bolt was investigated at elevated temperature. The A5056 bolt could reduce the bolt load loss compared to the SCM435 bolt due to smaller mismatch of thermal expansion between the bolt material and the plates. The mismatch of thermal expansion between bolt material and AZ91D plates was found to induce the compressive creep deformation in the AZ91D plates which performed as the main mechanism of bolt load loss. At higher tightening stress, the bolt load loss could be intensified by additional plastic deformation in bolt occurred during the test. Moreover, it is suggested that the plastic deformation could be reduced by decreasing the friction condition in the bolted joint.

A Study of Self-Loosening and Fatigue Failure of Bolted Joint under Transverse Vibration - Influences of Property Class of Bolt and Plastic Region Tightening

2007 ◽  
Vol 353-358 ◽  
pp. 2037-2040 ◽  
Author(s):  
Shinji Hashimura
Keyword(s):  
Fatigue Limit ◽  
Fatigue Failure ◽  
Transverse Vibration ◽  
Plastic Region ◽  
Fatigue Tests ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Transverse Vibrations ◽  
Fatigue Characteristics ◽  
Long Life

In our previous study, loosening-fatigue tests under small transverse vibrations had been performed to elucidate bolt behavior and loosening-fatigue mechanism in the long life region. In this study, the influences of bolt property class and the plastic region tightening on loosening-fatigue characteristics under transverse vibration have been investigated. Result shows that bolt property class has little influence on the loosening-fatigue limits under transverse vibration. Result also shows that the transverse loosening-fatigue limit of the bolt which has been tightened to within the plastic region is lower than the transverse loosening-fatigue limit of the bolt that has been tightened to within the elastic region. This result is the opposite of the result of the axial fatigue characteristics of bolted joints.

Determination of the Fatigue Properties of Aluminum Alloy Using Mini Specimen

2012 ◽  
Vol 726 ◽  
pp. 63-68 ◽  
Author(s):  
Tomasz Tomaszewski ◽  
Janusz Sempruch
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Strength ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Material Strength ◽  
Cyclic Tension ◽  
Static Tensile ◽  
6063 Aluminum Alloy ◽  
Fatigue Characteristics

There are situations where taking normative specimens is impossible due to the dimensions of the objects investigated (e.g. extruded sections) and one of the solutions is to use mini specimens. As for non-standard specimen testing, it is essential to define the effect of size on fatigue strength. The research methodology facilitates the determination of fatigue characteristics (S-N) for EN AW-6063 aluminum alloy. The material is used to manufacture the extruded section in the process of extrusion of the material through the extruding die. The methodology assumes the geometry of the mini specimen and the normative specimen. As for the material strength identification, a static tensile test for the specimens made directly from finished elements and preliminarily strained in cycles was carried out. As a result of the cyclic material reinforcement, an increase in yield strength Re was observed, which, in turn, rejects Re as the upper criterion of the high-cycle fatigue range. The essential fatigue tests were performed based on unilateral cyclic tension (R = 0.1). The effect of size on fatigue strength was defined. Theoretically aluminum alloy non-sensitive to changes in the size of the cross-section showed a different strength in mini and normative specimens.

ALCOA ALUMINUM ALLOY 7050

Alloy Digest ◽  
1990 ◽  
Vol 39 (1) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
High Temperature ◽  
Magnesium Alloy ◽  
Stress Corrosion Cracking ◽  
Heat Treating ◽  
Thin Sections ◽  
Aerospace Applications ◽  
Temperature Performance ◽  
Aluminum Company

Abstract ALCOA ALUMINUM ALLOY 7050 is an aluminum-zinc-copper-magnesium alloy with a superior combination of strength, stress-corrosion cracking resistance and toughness, particularly in thick sections. In thin sections it also possesses an excellent combination of properties that are important for aerospace applications. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, and joining. Filing Code: Al-233. Producer or source: Aluminum Company of America. Originally published as Aluminum 7050, January 1979, revised January 1990.

scholarly journals Fatigue Properties of AZ31B Magnesium Alloy Processed by Equal-Channel Angular Pressing

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1191
Author(s):  
Ryuichi Yamada ◽  
Shoichiro Yoshihara ◽  
Yasumi Ito
Keyword(s):  
Magnesium Alloy ◽  
Equal Channel Angular Pressing ◽  
Low Cycle Fatigue ◽  
Annealed Sample ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Angular Pressing ◽  
Fundamental Research ◽  
Number Of Cycles ◽  
Biodegradable Magnesium

A stent is employed to expand a narrowed tubular organ, such as a blood vessel. However, the persistent presence of a stainless steel stent yields several problems of late thrombosis, restenosis and chronic inflammation reactions. Biodegradable magnesium stents have been introduced to solve these problems. However, magnesium-based alloys suffer from poor ductility and lower than desired fatigue performance. There is still a huge demand for further research on new alloys and stent designs. Then, as fundamental research for this, AZ31 B magnesium alloy has been investigated for the effect of equal-channel angular pressing on the fatigue properties. ECAP was conducted for one pass and eight passes at 300 °C using a die with a channel angle of 90°. An annealed sample and ECAP sample of AZ31 B magnesium alloy were subjected to tensile and fatigue tests. As a result of the tensile test, strength in the ECAP (one pass) sample was higher than in the annealed sample. As a result of the fatigue test, at stress amplitude σa = 100 MPa, the number of cycles to failure was largest in the annealed sample, medium in the ECAP (one pass) sample and lowest in the ECAP (eight passes) sample. It was suggested that the small low cycle fatigue life of the ECAP (eight passes) sample is attributable to severe plastic deformation.

Newly Developed Heat Resistant Magnesium Alloy by Thixomolding®

2005 ◽  
Vol 488-489 ◽  
pp. 287-290 ◽  
Author(s):  
Tadayoshi Tsukeda ◽  
Ken Saito ◽  
Mayumi Suzuki ◽  
Junichi Koike ◽  
Kouichi Maruyama
Keyword(s):  
Aluminum Alloy ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Die Casting ◽  
The Other ◽  
Heat Resistant ◽  
Higher Temperature ◽  
Better Than

We compared the newly developed heat resistant magnesium alloy with conventional ones by Thixomolding® and aluminum alloy by die casting. Tensile properties at elevated temperatures of AXEJ6310 were equal to those of ADC12. In particular, elongation tendency of AXEJ6310 at higher temperature was better than those of the other alloys. Creep resistance of AXEJ6310 was larger than that of AE42 by almost 3 orders and smaller than that of ADC12 by almost 2 orders of magnitude. Fatigue limits at room temperature and 423K of AXEJ6310 was superior among conventional magnesium alloys.

Monotonic and Cyclic Characterization of Five Different Casting Processes on a Common Magnesium Alloy

2011 ◽  
Author(s):  
J. B. Jordon ◽  
L. Wang
Keyword(s):  
Magnesium Alloy ◽  
Mechanical Performance ◽  
Fatigue Crack Initiation ◽  
Low Pressure ◽  
Fatigue Tests ◽  
Microstructure Characterization ◽  
Cyclic Behavior ◽  
Permanent Mold ◽  
Az91 Magnesium Alloy ◽  
Az91 Magnesium

The monotonic and cyclic behavior of five different casting processes for AZ91 magnesium alloy is evaluated through microstructure characterization and mechanical testing. A passenger car control arm was cast by squeeze cast, low pressure permanent mold, low pressure permanent mold-electricmagnetic-pump, T-mag, and ablation processes. Samples were cut from twelve locations of the control arm for microstructure characterization. The grain size, porosity fraction, and porosity size were measured via optical microscopy. Different types and sizes of defects were present in each type of casting processes. The mechanical behavior characterization included monotonic tension, and fully-reversed fatigue tests. Sources of fatigue crack initiation were quantified using scanning electron microscopy. For both monotonic and cyclic loading conditions, poor mechanical performance was directly linked to the presence of large pores, oxide films, and/or pore shrinkage clusters.

Effect of Processing Layer on Fatigue Strength of Extruded AZ61 Magnesium Alloy

2013 ◽  
Vol 577-578 ◽  
pp. 429-432 ◽  
Author(s):  
Yukio Miyashita ◽  
Kyohei Kushihata ◽  
Toshifumi Kakiuchi ◽  
Mitsuhiro Kiyohara
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Magnesium Alloy ◽  
Crack Initiation ◽  
Crack Growth ◽  
Fatigue Crack Initiation ◽  
Fatigue Tests ◽  
Crack Growth Resistance ◽  
Az61 Magnesium Alloy

Fatigue Property of an Extruded AZ61 Magnesium Alloy with the Processing Layer Introduced by Machining was Investigated. Rotating Bending Fatigue Tests were Carried out with the Specimen with and without the Processing Layer. According to Results of the Fatigue Tests, Fatigue Life Significantly Increased by Introducing the Processing Layer to the Specimen Surface. Fatigue Crack Initiation and Propagation Behaviors were Observed by Replication Technique during the Fatigue Test. Fatigue Crack Initiation Life of the Specimen with the Processing Layer was Slightly Longer than that of the Specimen without the Processing Layer. Higher Fatigue Crack Growth Resistance was also Observed when the Fatigue Crack was Growing in the Processing Layer in the Specimen with the Processing Layer. the Longer Fatigue Life Observed in the Fatigue Test in the Specimen with the Processing Layer could be Mainly due to the Higher Crack Growth Resistance. it is Speculated that the Fatigue Strength can be Controlled by Change in Condition of Machining Process. it could be Effective way in Industry to Improved Fatigue Strength only by the Cutting Process without Additional Surface Treatment Process.

Thermal Fatigue Characteristics of Heat-Resisting Stainless Steel for Automotive Exhaust

2007 ◽  
Vol 539-543 ◽  
pp. 4944-4949 ◽  
Author(s):  
Tae Kwon Ha ◽  
Hwan Jin Sung
Keyword(s):  
Thermal Fatigue ◽  
Stainless Steels ◽  
Fatigue Property ◽  
Fatigue Tests ◽  
Fatigue Properties ◽  
Automotive Exhaust ◽  
Load Relaxation ◽  
Temperature Ranges ◽  
Fatigue Characteristics ◽  
Efficiency And Reliability

Thermal fatigue is a complex phenomenon encountered in materials exposed to cyclically varying temperatures in the presence or absence of external load. Continually increasing working temperature and growing need for greater efficiency and reliability of automotive exhaust require immediate investigation into the thermal fatigue properties especially of high temperature stainless steels. In this study, thermal fatigue properties of 304 and 429EM stainless steels have been evaluated in the temperature ranges of 200-800oC and 200-900oC. Systematic methods for control of temperatures within the predetermined range and measurement of load applied to specimens as a function of temperature during thermal cycles have been established. Thermal fatigue tests were conducted under fully constrained condition, where both ends of specimens were completely fixed. Thermal fatigue property of STS 304 was superior to that of STS 429EM. Load relaxation behavior at the temperatures of thermal cycle was closely related with the thermal fatigue property.

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