scholarly journals Evaluation of the Possibility of Obtaining Welded Joints of Plates from Al-Mg-Mn Aluminum Alloys, Strengthened by the Introduction of TiB2 Particles

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1564
Author(s):  
Ilya Zhukov ◽  
Alexander Kozulin ◽  
Anton Khrustalyov ◽  
Dmitrii Tkachev ◽  
Vladimir Platov ◽  
...  

In the work, the possibility of obtaining strong welded joints of aluminum alloys modified with particles is demonstrated. For research, strengthened aluminum alloys of the Al-Mg-Mn system with the introduction of TiB2 particles were obtained. TiB2 particles in specially prepared Al-TiB master alloys obtained by self-propagating high-temperature synthesis were introduced ex situ into the melt according to an original technique using ultrasonic treatment. Plates from the studied cast alloys were butt-welded by one-sided welded joints of various depths. To obtain welded joints, the method of electron beam welding was used. Mechanical properties of the studied alloys and their welded joints under tension were studied. It was shown that the introduction of particles resulted in a change in the internal structure of the alloys, characterized by the formation of compact dendritic structures and a decrease in the average grain size from 155 to 95 µm. The change in the internal structure due to the introduction of particles led to an increase in the tensile strength of the obtained alloys from 163 to 204 MPa. It was found that the obtained joints have sufficient relative strength values. Relative strength values reach 0.9 of the nominal strength of materials already at the ratio of the welded joint depth to the thickness of the welded plates, equal to 0.6 for the initial alloy and in the range of 0.67–0.8 for strengthened alloys.

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1030 ◽  
Author(s):  
Anton P. Khrustalyov ◽  
Alexander A. Kozulin ◽  
Ilya A. Zhukov ◽  
Marina G. Khmeleva ◽  
Alexander B. Vorozhtsov ◽  
...  

In the present study, aluminum alloys of the Al-Mg system with titanium diboride particles of different size distribution were obtained. The introduction of particles in the alloy was carried out using master alloys obtained through self-propagating high-temperature synthesis (SHS) process. The master alloys consisted of the intermetallic matrix Al-Ti with distributed TiB2 particles. The master alloys with TiB2 particles of different size distribution were introduced in the melt with simultaneous ultrasonic treatment, which allowed the grain refining of the aluminum alloy during subsequent solidification. It was found that the introduction of micro- and nanoparticles TiB2 increased the yield strength, tensile strength, and plasticity of as-cast aluminum alloys. After pass rolling the castings and subsequent annealing, the effect of the presence of particles on the increase of strength properties is much less felt, as compared with the initial alloy. The recrystallization of the structure after pass rolling and annealing was the major contributor to hardening that minimized the effect of dispersion hardening due to the low content of nanosized titanium diboride.


2020 ◽  
Vol 17 (6) ◽  
pp. 831-836
Author(s):  
M. Vykunta Rao ◽  
Srinivasa Rao P. ◽  
B. Surendra Babu

Purpose Vibratory weld conditioning parameters have a great influence on the improvement of mechanical properties of weld connections. The purpose of this paper is to understand the influence of vibratory weld conditioning on the mechanical and microstructural characterization of aluminum 5052 alloy weldments. An attempt is made to understand the effect of the vibratory tungsten inert gas (TIG) welding process parameters on the hardness, ultimate tensile strength and microstructure of Al 5052-H32 alloy weldments. Design/methodology/approach Aluminum 5052 H32 specimens are welded at different combinations of vibromotor voltage inputs and time of vibrations. Voltage input is varied from 50 to 230 V at an interval of 10 V. At each voltage input to the vibromotor, there are three levels of time of vibration, i.e. 80, 90 and 100 s. The vibratory TIG-welded specimens are tested for their mechanical and microstructural properties. Findings The results indicate that the mechanical properties of aluminum alloy weld connections improved by increasing voltage input up to 160 V. Also, it has been observed that by increasing vibromotor voltage input beyond 160 V, mechanical properties were reduced significantly. It is also found that vibration time has less influence on the mechanical properties of weld connections. Improvement in hardness and ultimate tensile strength of vibratory welded joints is 16 and 14%, respectively, when compared without vibration, i.e. normal weld conditions. Average grain size is measured as per ASTM E 112–96. Average grain size is in the case of 0, 120, 160 and 230 is 20.709, 17.99, 16.57 and 20.8086 µm, respectively. Originality/value Novel vibratory TIG welded joints are prepared. Mechanical and micro-structural properties are tested.


2013 ◽  
Vol 721 ◽  
pp. 282-286
Author(s):  
Guang Hui Qi

In order to settle environment pollution and provide a high effective and low-cost modifier for refining the primary Si in hypereutectic Al-Si alloys, Al-Fe-P master alloys containing 2.0~5.0% phosphorus have been invented by casting method. The Al-Fe-P master alloys can be conveniently produced and an excellent modification can be obtained by adding 0.3~0.8wt% Al-Fe-P master alloy in Al-Si alloys containing 12%-25% Si at a relatively lower modifying temperature. The number of primary Si increases obviously and the average grain size of primary Si decreases largely, less than 50μm. Furthermore Al-Fe-P master alloys have many advantages, such as low cost, convenient operation technology, no pollution, stable and long-term modification effect, easy storage and etc. Al-Fe-P master alloys have overcome the shortages of current modifier and have a good future for hypereutectic Al-Si alloy modification.


Author(s):  
Aleksandr B. VOROZHTSOV ◽  
◽  
Vladimir V. PLATOV ◽  
Aleksandr A. KOZULIN ◽  
Anton P. KHRUSTALEV ◽  
...  

In this work, the special master alloys containing aluminum and TiB2 powder with bimodal particle size distribution in three mixture compositions are prepared. The master alloys are infused into the melts using an external ultrasound source. The castings with particles had smaller grain sizes than the initial castings without particles. It is found that the hardness, yield strength, and ultimate tensile strength reach higher values with an increase in the relative elongation of the cast alloys with added particles. A warm rolling mode is employed for the studied alloys to obtain sheet blanks. It is shown that the staged shrinkage of the billets up to deformation of 80 % with periodic heating up to 300 °C allows one to obtain defect-free sheet products. The structure of the rolled sheet-alloys is characterized by the plate-shaped grains elongated along the rolling direction with pockets of submicron-sized grains in between. The strength properties of the studied rolled alloys exceeded those of the cast alloys. In the case of the rolled alloys, an increase in the yield strength, ultimate tensile strength, and ductility is revealed for the alloys with particles as compared to the ones with no particles added.


2021 ◽  
Vol 2079 (1) ◽  
pp. 012022
Author(s):  
Yongchao Jian ◽  
Yan Shi

Abstract Because of the uneven distribution of reinforcement particles in the molten pool during laser welding of SiCp/6061Al composites with powder, the effect of pulse frequency on the homogenization was studied in this paper. The pulse frequency of welding is changed and the macro morphology of the weld is studied by metallographic microscope. The particle uniformity of reinforcing phase and the porosity of molten pool at different frequencies were compared. The tensile strength of welded joints at different frequencies was tested by universal tensile machine. Finally, when the pulse frequency is 160Hz, the particle distribution of reinforcing phase is the most uniform and the tensile strength is the largest. The tensile strength reaches 267.06MPa, reaching 69.1% of the base metal. When the pulse frequency is 320Hz, the porosity of the weld is the lowest, reaching 1.75%.


2019 ◽  
Vol 91 (10) ◽  
pp. 7-15
Author(s):  
Tomasz Piwowarczyk ◽  
Marcin Korzeniowski ◽  
Dawid Majewski

This article explores the possibilities of using non-destructive ultrasonic techniques to analyze the quality of lapped braze-welded joints. The tests were performed for 4 material groups (DC03+ZE steel and X5CrNi18-19 steel, aluminum alloys AW-5754 and AW-6061, titanium Grade 2 and copper Cu-ETP). As part of the work, additional materials and joint processes and its parameters were selected (TIG, MIG, laser). The quality of joints was monitored using scanning acoustic microscopy. Based on the A-scan andC-scan images, potential joints imperfections were determined. The possibilities of using advanced ultrasonic techniques to analyze the quality of braze joints was assessed.


2021 ◽  
pp. 34-43
Author(s):  
A.V. Sviridov ◽  
◽  
М.S. Gribkov ◽  

The technology of electron-beam welding (EBW) of structures of large thickness made of titanium alloy Ti–6Al–4V has been developed. A complex of metallographic studies of welded samples has been carried out. Tests to determine the mechanical characteristics of repair welded joints, that these joints made by EBW are equal in strength to the base material. The analysis of the level of residual stresses in various parts of the welded joint after repeated repair passes has been carried out. It was found that the subsequent vacuum annealing reduces the level of residual stresses in welded joints to 50 %. The analysis of the elemental composition showed that the elemental composition of the samples from the center of the weld to the base metal practically does not change for welding with the number of repeated passes up to 3.


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