Investigation and Optimization of Laser Welding of Ti-6Al-4V Titanium Alloy Plates

2013 ◽  
Author(s):  
Fabrizia Caiazzo ◽  
Vittorio Alfieri ◽  
Gaetano Corrado ◽  
Francesco Cardaropoli ◽  
Vincenzo Sergi
Keyword(s):  
Laser Welding ◽  
Titanium Alloys ◽  
Arc Welding ◽  
Laser Source ◽  
Plasma Arc Welding ◽  
Butt Welding ◽  
Specific Strength ◽  
High Specific Strength ◽  
Welding Defects ◽  
Set Up

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.

Investigation and Optimization of Laser Welding of Ti-6Al-4 V Titanium Alloy Plates

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Fabrizia Caiazzo ◽  
Vittorio Alfieri ◽  
Gaetano Corrado ◽  
Francesco Cardaropoli ◽  
Vincenzo Sergi
Keyword(s):  
Laser Welding ◽  
Titanium Alloys ◽  
Beam Quality ◽  
Tensile Tests ◽  
Laser Source ◽  
Face Centered Cubic ◽  
Butt Welding ◽  
Specific Strength ◽  
Wide Range ◽  
Predicted Values

Titanium alloys are employed in a wide range of applications, from aerospace to medicine. In particular, Ti-6Al-4 V 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 are indeed achieved; moreover, a smaller grain size in the fused zone (FZ) is benefited in comparison to either tungsten inert gas (TIG) or plasma arc welding, thus improving the tensile strength of the welded structures. This study was carried out on 3 mm thick Ti-6Al-4 V plates in square butt welding configuration. The novelty element of the investigation is the use of a disk-laser source, which allows a number of benefits thanks to better beam quality; furthermore, a proper device was developed for bead protection, as titanium is prone to oxidation when in fused state. A three-level factorial plan was arranged in face-centered cubic scheme. The regression models were found for a number of crucial responses and the corresponding surfaces were discussed; then a numerical optimization was carried out. The suggested condition was evaluated to compare the actual responses to the predicted values; X-ray inspections, Vickers micro hardness tests, and tensile tests were performed for the optimum.

Investigation and Optimization of Disk-Laser Welding of 1 MM Thick Ti-6Al-4V Titanium Alloy Sheets

2014 ◽  
Author(s):  
Fabrizia Caiazzo ◽  
Vittorio Alfieri ◽  
Ilaria Fierro ◽  
Vincenzo Sergi
Keyword(s):  
Arc Welding ◽  
Numerical Optimization ◽  
Structural Changes ◽  
Desirability Function ◽  
Laser Beam Welding ◽  
Laser Source ◽  
Space Vehicles ◽  
Plasma Arc Welding ◽  
Butt Welding ◽  
Disk Laser

Welded Ti-6Al-4V joints are employed in nuclear engineering, civil industries, military and space vehicles. Laser beam welding has been used for welding thanks to its advantages in terms of increase in penetration depth and reduction of possible defects; 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 and test the regression model for a number of crucial responses. The study has been carried out on 1 mm thick Ti-6Al-4V plates; a square butt welding configuration was considered employing a disk-laser source. A three level Box-Behnken experimental design is considered. An optimum condition has been suggested via numerical optimization of the desirability function with proper weights and importance of constraints. Vickers micro hardness testing was conducted to discuss structural changes in fused and heat affected zone.

Research Progress of the Surface Oxidation of Titanium and its Alloys

2013 ◽  
Vol 748 ◽  
pp. 188-191
Author(s):  
Hui Jun Yu
Keyword(s):  
Titanium Alloys ◽  
Biomedical Applications ◽  
Influence Factors ◽  
Surface Oxidation ◽  
Research Progress ◽  
Corrosion Resistant ◽  
Specific Strength ◽  
Existing Problems ◽  
High Specific Strength ◽  
Micro Arc Oxidation

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.

scholarly journals Relationship among Welding Defects with Convection and Material Flow Dynamic Considering Principal Forces in Plasma Arc Welding

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1444
Author(s):  
Huu Loc Nguyen ◽  
Anh Van Nguyen ◽  
Han Le Duy ◽  
Thanh-Hai Nguyen ◽  
Shinichi Tashiro ◽  
...  
Keyword(s):  
Weld Pool ◽  
Material Flow ◽  
Arc Welding ◽  
Welding Current ◽  
Plasma Arc Welding ◽  
Plasma Arc ◽  
Flow Dynamic ◽  
Pool Surface ◽  
Welding Defects ◽  
Marangoni Force

The material flow dynamic and velocity distribution on the melted domain surface play a crucial role on the joint quality and formation of welding defects. In this study, authors investigated the effects of the low and high currents of plasma arc welding on the material flow and thermodynamics of molten pool and its relationship to the welding defects. The high-speed video camera (HSVC) was used to observe the convection of the melted domain and welded-joint appearance. Furthermore, to consider the Marangoni force activation, the temperature on the melted domain was measured by a thermal HSVC. The results revealed that the velocity distribution on the weld pool surface was higher than that inside the molten weld pool. Moreover, in the case of 80 A welding current, the convection speed of molten was faster than that in other cases (120 A and 160 A). The serious undercut and humping could be seen on the top surface (upper side) and unstable weld bead was visualized on the back side (bottom surface). In the case of 160 A welding current, the convection on the weld pool surface was much more complex in comparison with 80 A and 120 A cases. The excessive convex defect at the bottom side and the concave defect at the top surface were observed. In the case of 120 A welding current, two convection patterns with the main flow in the backward direction were seen. Almost no welding defect could be found. The interaction between the shear force and Marangoni force played a solid state on the convection and heat transportation processes in the plasma arc welding process.

An Experimental Investigation Into the High Speed Turning of Ti-6Al-4V Titanium Alloy

2010 ◽  
Author(s):  
Anil K. Srivastava ◽  
Jon Iverson
Keyword(s):  
Titanium Alloy ◽  
Titanium Alloys ◽  
High Speed ◽  
Elevated Temperatures ◽  
Chemical Reactivity ◽  
Specific Strength ◽  
Aerospace Applications ◽  
Layered Coatings ◽  
High Specific Strength ◽  
Cutting Speeds

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.

Influence of the composition of α-titanium alloys on thermal conductivity

2021 ◽  
pp. 79-86
Author(s):  
I. A. Schastlivaya ◽  
V. P. Leonov ◽  
I. V. Tretyakov ◽  
A. Yu. Askinazi
Keyword(s):  
Thermal Conductivity ◽  
Titanium Alloys ◽  
Nuclear Power ◽  
Power Plants ◽  
Operating Temperature ◽  
Unique Combination ◽  
Specific Strength ◽  
High Specific Strength ◽  
Heat Exchange Equipment ◽  
Materials Used

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. 

Determining High-Temperature Oxidation Resistance of (TI-Al-X-N) Based Coatings for Titanium Alloys

2021 ◽  
Vol 320 ◽  
pp. 66-71
Author(s):  
Konstantins Savkovs ◽  
Margarita Urbaha ◽  
Viktors Feofanovs
Keyword(s):  
Titanium Alloys ◽  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Resistance Testing ◽  
Maximum Efficiency ◽  
Temperature Oxidation ◽  
Turbine Engine ◽  
Specific Strength ◽  
High Specific Strength ◽  
Pressure Part

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.

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 ◽  
...  
Keyword(s):  
Titanium Alloys ◽  
Automotive Industry ◽  
Stress Ratio ◽  
Small Deformation ◽  
Aircraft Fuselage ◽  
Specific Strength ◽  
High Specific Strength ◽  
Processing Cost ◽  
Deformation Coefficient ◽  
Very High

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.

Microstructural Behaviors of Boron Modified LCB Titanium Alloy

2014 ◽  
Vol 1025-1026 ◽  
pp. 601-604 ◽  
Author(s):  
Tae Yong Kim ◽  
Dong Geun Lee ◽  
Ka Ram Lim ◽  
Kyung Mok Cho ◽  
Yong Tae Lee
Keyword(s):  
Titanium Alloys ◽  
Low Cost ◽  
Jet Engine ◽  
Cast Ingot ◽  
Specific Strength ◽  
Good Corrosion Resistance ◽  
High Specific Strength ◽  
Beta Titanium ◽  
Low Elastic Modulus ◽  
Beta Titanium Alloys

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.

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