scholarly journals Analysis and Research of the High-Cycle Fatigue Fracture Mode Based on Stress Ratio and Residual Stress of Ti-6Al-4V

2022 ◽  
Vol 2022 ◽  
pp. 1-9
Author(s):  
Fu Wang ◽  
Jian-Jun Wang ◽  
Qin-Sheng Li ◽  
Guo-Zhu Ren ◽  
Xin-Jian Zhang ◽  
...  

The content of titanium is about 0.63% in the earth’s crust, and it ranks 10th among all elements. The content of titanium is next to the metal elements of aluminum, iron and magnesium, iron, and magnesium; titanium alloys have low density, high specific strength (the ratio of tensile strength to density), wide working range (−253°C–600°C), and excellent corrosion resistance melting point; the chemical activity of titanium alloy is very high, and it easily reacts with hydrogen, oxygen, and nitrogen, so it is difficult to be smelted and processed, and the processing cost is high. Titanium alloys also have poor thermal conductivity (only 1/5 of iron and 1/15 of aluminum), small deformation coefficient, large friction coefficient, and other characteristics. They are widely used in aircraft fuselage, gas turbine, petrochemical, automotive industry, medical, and other fields for important parts.

2013 ◽  
Vol 748 ◽  
pp. 188-191
Author(s):  
Hui Jun Yu

Titanium and titanium alloys possess some attractive properties, such as excellent corrosion and erosion resistance, low densities, high specific strength and modulus, enabling them extensively used in aeronautical, marine, chemical and biomedical applications and so on. Nevertheless, Recent years, the corrosion resistance of titanium and titanium alloys is required to elevate in some fields, proper surface modification such as surface oxidation can solve the problems effectively. In this paper, the recent investigations of thermal oxidation and micro-arc oxidation to improve the corrosion resistant of titanium and its alloys are reviewed. The structures, properties and their influence factors of the coatings are analysed systematically. And the existing problems and the future prospect of the further researches is mentioned.


Author(s):  
Anil K. Srivastava ◽  
Jon Iverson

Titanium and its alloys have seen increased utilization in military and aerospace applications due to combination of high specific strength, toughness, corrosion resistance, elevated-temperature performance and compatibility with polymer composite materials. Titanium alloys are difficult to machine due to their inherent low thermal conductivity and higher chemical reactivity with other materials at elevated temperatures. In general, temperature related machining difficulties are encountered at production speeds in the range of 60 m/min and high-speed machining of these alloys has created considerable interest to researchers, tool manufacturers and end users. This paper provides recent results obtained during turning operation with the aim of improving machinability of titanium alloys. Several tests have been conducted using (i) micro-edge prep geometry of the inserts, (ii) ultra-hard PVD coated, and (iii) nano-layered coated inserts and the effects of speeds and feeds during turning of Ti-6Al-4V titanium alloy are discussed. The initial tests have been conducted under orthogonal (2-D) cutting conditions with no coolant application. Based on these results, several oblique cutting (3-D) tests have been designed and conducted to study the effect of various types of ultra-hard and nano-layered coatings at higher cutting speeds under flooded coolant conditions. The effects of speed and feed on cutting force and tool wear are presented in this paper.


Author(s):  
I. A. Schastlivaya ◽  
V. P. Leonov ◽  
I. V. Tretyakov ◽  
A. Yu. Askinazi

Among titanium alloys, modern α- and pseudo-α-alloys occupy a special place due to the unique combination of their mechanical properties, corrosion resistance, low density and high specific strength, which determines their effectiveness in various industries. Analysis of structural materials used for heat exchange equipment of nuclear power plants showed that the increase in the efficiency and compactness of tube systems made of a-titanium alloys is constrained by their thermal conductivity characteristic, which does not exceed 89 W/(m·K) at a temperature of 20°C. An exception is the VT1-0 grade alloy, the scope of which is limited to a maximum operating temperature of no more than 250°C. The paper considers the results of studies of a new titanium alloy of the Ti-Zr-Al-O composition with increased thermal conductivity for pipe systems of power equipment. 


2021 ◽  
Vol 320 ◽  
pp. 66-71
Author(s):  
Konstantins Savkovs ◽  
Margarita Urbaha ◽  
Viktors Feofanovs

Basic titanium alloys are successfully used in modern aviation GTE (gas turbine engine). They are used for parts of a compressor and partly in low pressure part of turbine (intermetallic Ti-Al alloys) due to their high specific strength and at the same time low density, high corrosion resistance but can be used only up to 700 °C. The paper deals with the results of heat resistance testing at 750 °C of Ti-Al-(X)+N based thin ion-plasm multilayers coatings, with different priority of monolayers- intermetallic, conglomerate or nitride for gas turbine engine (GTE) blades from titanium alloys. All coatings showed high resistance during the test, with a maximum efficiency 42.8 of coating with a priority of conglomerate after 30 hours of testing.


Author(s):  
P G Allen

Titanium alloys offer unique specific strength, fatigue and temperature capability characteristics. Substitution for steel in reciprocating engine components offers potential improvements in performance, vibration reduction and fuel efficiency. Issues such as alloy selection, processing, cost, benefits and demerits of using titanium for these components are addressed.


Aerospace ◽  
2006 ◽  
Author(s):  
Yong-Hyun Lee ◽  
Ji-Eun Choi ◽  
Ki-Ju Kang

Periodic cellular metals (PCM), especially truss PCM's seem promising as new materials in 21 century. Various works have been performed for the mechanical and thermal performance. However, only a number of papers have been published regarding fabrication techniques of PCM, even though the techniques should determine whether PCM's is survived in the future market, or not. In this work a new type of PCM with Kagome trusses is presented. Continuous metal wires as the raw materials are assembled in six directions with least deflection, which gives very high specific strength and stiffness. The mechanical behavior under compression and bending of hand-made specimens is presented. Also, the benefits and features are discussed.


2012 ◽  
Vol 191 ◽  
pp. 123-130
Author(s):  
Stanisław Roskosz ◽  
Bartłomiej Dybowski ◽  
Jan Cwajna

Magnesium alloys, thanks to their low density, are characterized by very high specific strength and specific stiffness. Due to acceptable mechanical properties, these alloys are widely used in automotive and aerospace industries for the elements such as: gearbox and engine housings, steering wheel columns or wheels. The main problem of the most common magnesium alloys – such as AZ91 are their weak high temperature properties. This led to development of alloys containing rare earth elements. These alloys achieve their demanded mechanical properties after grain refinement with the zirconium. Because of a big responsibility of the elements made from Mg-RE alloys, it is important to investigate modification impact on properties of the magnesium alloys. The paper presents results of studies properties of the WE43 and Elektron 21 casting magnesium alloys, modified in three different ways – according to Magnesium-Elektron specification, 50% stronger modification and 100% stronger. For the comparison, unmodified alloys were also investigated. Investigations showed, that alloys modified according to MEL specification presents optimal set of structural and mechanical properties. Further increase of amount of modifiers doesn’t let to significant increase of mechanical properties. Fractographic investigations showed many non-metallic inclusions on the fractures surface, which are result of faulty smelting process.


2014 ◽  
Vol 1025-1026 ◽  
pp. 601-604 ◽  
Author(s):  
Tae Yong Kim ◽  
Dong Geun Lee ◽  
Ka Ram Lim ◽  
Kyung Mok Cho ◽  
Yong Tae Lee

Titanium has high specific strength, low elastic modulus, and good corrosion resistance. Especially, beta titanium alloys are used for jet engine, turbine blade in automobile and aerospace industries because of its good formability. Among the beta titanium alloys, LCB (Low-Cost Beta) titanium alloys were developed to make economical and mechanical advantages by not using high-cost beta stabilizer like Nb, Zr, Ta but using low-cost beta stabilizer like Mo, Fe, Cr, etc. In LCB titanium alloys, adding a small amount of boron makes grain refinement in cast ingot. This study has analyzed the changes of microstructure which can change mechanical properties after heat treatment and the plastic deformation in case of adding a small amount of boron.


Author(s):  
Fabrizia Caiazzo ◽  
Vittorio Alfieri ◽  
Gaetano Corrado ◽  
Francesco Cardaropoli ◽  
Vincenzo Sergi

Titanium alloys are employed for several applications, ranging from aerospace to medicine. In particular, Ti-6Al-4V is the most common, thanks to an excellent combination of low density, high specific strength and corrosion resistance. Laser welding has been increasingly considered as an alternative to traditional techniques to join titanium alloys. An increase in penetration depth and a reduction of possible welding defects is achieved indeed; moreover a smaller grain size in the fused zone is benefited in comparison to either TIG and plasma arc welding, thus providing an increase in the tensile strength of the welded structures. The aim of this work is to develop the regression model for a number of responses which are crucial for the feature of the joint. The study was carried out on 3 mm thick Ti-6Al-4V plates; a square butt welding configuration was considered employing a disk-laser source. A 3-level factorial plan was hence arranged in a face-centred cubic scheme. The responses were analyzed referring to the governing parameters. Then, an optimization was carried out via statistical tools, in order to find the optimal welding set-up for the alloy under examination.


2013 ◽  
Vol 748 ◽  
pp. 184-187 ◽  
Author(s):  
Hui Jun Yu

Titanium and titanium alloys are widely used in aeronautical, marine, chemical and biomedical applications and so on, owing to their specific properties such as good corrosion resistance, low densities, high specific strength and modulus, and high-temperature resistance. However titanium and titanium alloys also have many disadvantages, such as low hardness, low wear-resistance and the low corrosion-resistance in some cases, which limit their wider application. Recent years, the corrosion resistance of titanium and titanium alloys is required to elevate in some fields. Proper surface modification can solve the problems effectively. This paper reviews the recent investigations of laser surface modification to improve the corrosion resistant of titanium and its alloys. The microstructures, the corrosion resistance properties, and the influence factors of the coatings were discussed systematically. And the future prospect of the further researches and uses is presented.


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