scholarly journals The Effect of Oxide Film on the Strength of an Ultrasonically Welded Joint, and Welding Process. Study on the Ultrasonic Welding of Dissimilar Metals. (2nd report).

1999 ◽  
Vol 17 (2) ◽  
pp. 234-242 ◽  
Author(s):  
Takehiko WATANABE ◽  
Akihiko YONEDA ◽  
Atushi YANAGISAWA ◽  
Shizuyo KONUMA ◽  
Osamu OHASHI
Keyword(s):  
Oxide Film ◽  
Welded Joint ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Dissimilar Metals ◽  
Process Study

Features of the Heating Process in Ultrasonic Welding of Polycarbonate Products under Independent Pressure

2020 ◽  
pp. 54-62
Author(s):  
S.S. Volkov ◽  
A.L. Remizov ◽  
A.S. Pankratov
Keyword(s):  
Welded Joints ◽  
Welded Joint ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Heating Process ◽  
Mechanism Of Formation ◽  
High Quality ◽  
Acoustic Contact ◽  
Welding Pressure

This paper presents a mechanism of formation of a hard-to-weld polycarbonate joint by ultrasonic welding. The method utilizes internal and external friction occurring in the welded joint area on abutting surfaces due to shear vibrations of the end of the upper part relative to the lower part. A layer of the heated welded material is formed, localized by thickness, in which predominant absorption of the ultrasonic vibrations occurs, which allows one to obtain high-quality and durable welded joints without significant deformation due to the concentration of thermal energy in the welding zone. The effect of independent welding pressure on the strength of the welded joint of polycarbonate is considered. A new method of ultrasonic welding under the conditions of independent pressure is proposed. The method consists of dividing the static welding pressure into two components: the pressure of the acoustic contact in the zone of contact of the waveguide with the product, and the welding pressure that compresses the welded products, with the latter component being lower than the former. In order to obtain high-quality welded joints made of polycarbonate and to prevent displacement of the welded edges during the welding process relative to each other, a special preparation of the welded edges is developed, which allows one part to be moved vertically relative to the other during the welding process. It is established that the quality of welding depends on the speed of movement and the angle of cutting the edges.

Analysis about the Jointing Status for Dissimilar Metals of Steel with Magnesium

2012 ◽  
Vol 233 ◽  
pp. 374-379 ◽  
Author(s):  
Zong Xiang Yao ◽  
De Ping Jiang ◽  
Chao Pan ◽  
Xiao Ming Wang
Keyword(s):  
Adverse Effect ◽  
Intermetallic Compound ◽  
Laser Welding ◽  
Welded Joint ◽  
Welding Process ◽  
Dissimilar Metals ◽  
Hybrid Welding ◽  
Pressure Welding ◽  
Diffusion Brazing ◽  
Welding Pressure

The research status of welding process between magnesium with steel have been surveyed．This article detailed the laser welding, Laser-TIG hybrid welding, pressure welding,diffusion brazing. The paper pointed out that it is a prominent problem of magnesium to be oxidated easily and existing intermetallic compound in the joint, which will produce adverse effect to property of welded joint. So how to control morphology and existence state of intermetallic compound (IMC) is the key for quality connectors in joining of magnesium with steel.

scholarly journals Development and Evaluation of the Ultrasonic Welding Process for Copper-Aluminium Dissimilar Welding

2022 ◽  
Vol 6 (1) ◽  
pp. 6
Author(s):  
Rafael Gomes Nunes Silva ◽  
Sylvia De Meester ◽  
Koen Faes ◽  
Wim De Waele
Keyword(s):  
Cross Sections ◽  
Welding Process ◽  
Weld Interface ◽  
Ultrasonic Welding ◽  
Dissimilar Welding ◽  
Dissimilar Metals ◽  
Weld Quality ◽  
Metallographic Examination ◽  
Metallurgical Defects ◽  
The Impact

The demand for joining dissimilar metals has exponentially increased due to the global concerns about climate change, especially for electric vehicles in the automotive industry. Ultrasonic welding (USW) surges as a very promising technique to join dissimilar metals, providing strength and electric conductivity, in addition to avoid metallurgical defects, such as the formation of intermetallic compounds, brittle phases and porosities. However, USW is a very sensitive process, which depends on many parameters. This work evaluates the impact of the process parameters on the quality of ultrasonic spot welds between copper and aluminium plates. The weld quality is assessed based on the tensile strength of the joints and metallographic examination of the weld cross-sections. Furthermore, the welding energy is examined for the different welding conditions. This is done to evaluate the influence of each parameter on the heat input resulting from friction at the weld interface and on the weld quality. From the obtained results, it was possible to optimise parameters to achieve satisfactory weld quality in 1.0 mm thick Al–Cu plate joints in terms of mechanical and metallurgical properties.

scholarly journals Investigation of Imperfections Formed at the Ultrasonic Welding of Copper Sheets

2019 ◽  
Vol 2 (1) ◽  
pp. 43-48
Author(s):  
Tünde Anna Kovács
Keyword(s):  
Colour Change ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Welding Parameters ◽  
Dissimilar Metals ◽  
Thin Sheets ◽  
Work Time ◽  
Welding Defects

Abstract Ultrasonic welding is a very useful and simple welding process. It is suitable for establishing a joint between thin sheets and dissimilar metals with short preparation and finish work time [1]. Some welding defects were detected due to less than optimal ultrasonic welding parameters. These defects were ruptures, surface colour change and unacceptable deformations. This article aims to identify these failures and their causes.

scholarly journals Static ultrasonic welding of carbon fibre unidirectional thermoplastic materials and the influence of heat generation and heat transfer

2021 ◽  
pp. 002199832097681
Author(s):  
F Köhler ◽  
IF Villegas ◽  
C Dransfeld ◽  
A Herrmann
Keyword(s):  
Cross Sections ◽  
Weld Line ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Thermoplastic Composites ◽  
Squeeze Flow ◽  
Anisotropic Flow ◽  
Lap Shear ◽  
Anisotropic Thermal Conductivity ◽  
Edge Defects

Ultrasonic welding is a promising technology to join fibre-reinforced thermoplastic composites. While current studies are mostly limited to fabric materials the applicability to unidirectional materials, as found in aerospace structures, would offer opportunities for joining primary aircraft structures. However, due to the highly anisotropic flow of a molten unidirectional ply undesired squeeze flow phenomena can occur at the edges of the weld overlap. This paper investigates how the fibre orientation in the plies adjacent to the weld line influences the welding process and the appearance of edge defects. Ultrasonic welding experiments with different layups and energy director configurations were carried out while monitoring temperatures at different locations inside and outside the weld overlap. The joints were characterized by single lap shear tests, analysis of corresponding fracture surfaces and microscopic cross-sections. Results showed that the anisotropic flow and the anisotropic thermal conductivity of the plies adjacent to the weld line have a distinct effect on the appearance and location of edge defects. By using energy directors that cover only part of the weld overlap area a new approach was developed to mitigate edge defects caused by the highly directional properties of the unidirectional plies.

Experimental Investigations on Aluminium Ultrasonic Welding Parameters

2014 ◽  
Vol 657 ◽  
pp. 306-310
Author(s):  
Lăcrămioara Apetrei ◽  
Vasile Rață ◽  
Ruxandra Rață ◽  
Elena Raluca Bulai
Keyword(s):  
Microstructural Analysis ◽  
Base Material ◽  
Welding Process ◽  
Ultrasonic Welding ◽  
Experimental Investigations ◽  
Welding Parameters ◽  
Material Structure ◽  
Welding Temperature ◽  
Wide Range ◽  
Made In

Research evolution timely tendencies, in the nonconventional technologies field, are: manufacture conditions optimization and complex equipments design. The increasing of ultrasonic machining use, in various technologies is due to the expanding need of a wide range materials and high quality manufacture standards in many activity fields. This paper present a experimental study made in order to analyze the welded zone material structure and welding quality. The effects of aluminium ultrasonic welding parameters such as relative energy, machining time, amplitude and working force were compared through traction tests values and microstructural analysis. Microhardness tests were, also, made in five different points, two in the base material and three in the welded zone, on each welded aluminium sample. The aluminum welding experiments were made at the National Research and Development Institute for Welding and Material Testing (ISIM) Timişoara. The ultrasonic welding temperature is lower than the aluminium melting temperature, that's so our experiments reveal that the aluminium ultrasonic welding process doesn't determine the appearance of moulding structure. In the joint we have only crystalline grains deformation, phase transformation and aluminium diffusion.

Influence of Friction Stir Welding Process on the Weld Formation and Tensile Strength of Titanium and Aluminum Dissimilar Alloys Welded Joint

2011 ◽  
Vol 189-193 ◽  
pp. 3266-3269 ◽  
Author(s):  
Yu Hua Chen ◽  
Peng Wei ◽  
Quan Ni ◽  
Li Ming Ke
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Cross Section ◽  
Welded Joint ◽  
Welding Process ◽  
Dissimilar Materials ◽  
Influence Of Process Parameters ◽  
Friction Stir ◽  
Dissimilar Alloys ◽  
Titanium Aluminum

Titanium alloy TC1 and Aluminum alloy LF6 were jointed by friction stir welding (FSW), and the influence of process parameters on formation of weld surface, cross-section morphology and tensile strength were studied. The results show that, Titanium and Aluminum dissimilar alloy is difficult to be joined by FSW, and some defects such as cracks and grooves are easy to occur. When the rotational speed of stir head(n) is 750r/min and 950r/min, the welding speed(v) is 118mm/min or 150mm/min, a good formation of weld surface can be obtained, but the bonding of titanium/aluminum interface in the cross-section of weld joint is bad when n is 750r/min which results in a low strength joint. When n is 950r/min and v is 118mm/min，the strength of the FSW joint of Titanium/Aluminum dissimilar materials is 131MPa which is the highest．

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