Constitutive equation including acoustic stress work and plastic strain for modeling ultrasonic vibration assisted friction stir welding process

Zhao, Wanhua; Chen, Wu

doi:10.1016/j.ijmachtools.2019.103434

Cited by 48 publications

(13 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Colegrove et al [29,30] proposed a linear empirical softening rule to calculate the flow stress of aluminum alloys when the temperature is close to the solidus temperature in the analysis of the heat generation and material flow of FSW processes. Due to the limitation in the temperature range of the Sellars-Tegart equation, other nonlinear terms [31][32][33] were adopted to calculate the flow stress when the temperature is close to the solidus temperature. However, the current methods for predicting the flow stress at the typical FSW temperature were empirical.…”

Section: Introductionmentioning

confidence: 99%

Flow Stress of 6061 Aluminum Alloy at Typical Temperatures during Friction Stir Welding Based on Hot Compression Tests

Ding¹,

Shi

Chen

2021

Metals

View full text Add to dashboard Cite

The purpose of this paper is to report quantitative data and models for the flow stress for the computer simulation of friction stir welding (FSW). In this paper, the flow stresses of the commercial 6061 aluminum alloy at the typical temperatures in FSW are investigated quantitatively by using hot compression tests. The typical temperatures during FSW are determined by reviewing the literature data. The measured data of flow stress, strain rate and temperature during hot compression tests are fitted to a Sellars–Tegart equation. An artificial neural network is trained to implement an accurate model for predicting the flow stress as a function of temperature and strain rate. Two models, i.e., the Sellars–Tegart equation and artificial neural network, for predicting the flow stress are compared. It is found that the root-mean-squared error (RMSE) between the measured and the predicted values are found to be 3.43 MPa for the model based on the Sellars–Tegart equation and 1.68 MPa for the model based on an artificial neural network. It is indicated that the artificial neural network has better flexibility than the Sellars–Tegart equation in predicting the flow stress at typical temperatures during FSW.

show abstract

Section: Introductionmentioning

confidence: 99%

Flow Stress of 6061 Aluminum Alloy at Typical Temperatures during Friction Stir Welding Based on Hot Compression Tests

Ding¹,

Shi

Chen

2021

Metals

View full text Add to dashboard Cite

show abstract

“…Since the electrical conductivity is related to the ordinary diffusion coefficient, referring to Equation (31), we can get the formula to calculate the electrical conductivity when ultrasound is applied: where v z and v r are the components of vibration velocity in z and r directions, respectively. Assuming that the vibration is emitted from the tip of the tungsten electrode, due to the phase difference between the vibrations at different positions [48], we have,…”

Section: (4) Electrical Conductivity Variation Induced By Ultrasoundmentioning

confidence: 99%

Effects of Ultrasonic Vibration on the Transport Coefficients in Plasma Arc Welding

Chen

2020

Metals

Self Cite

View full text Add to dashboard Cite

In ultrasound assisted plasma arc welding (U-PAW), the exerted ultrasonic vibration on the tungsten electrode interacts with the plasma arc and changes its heat-pressure characteristics. It is of great significance to investigate the underlying interaction mechanism. In this study, the calculation method of transport coefficients in U-PAW is developed. Translational thermal conductivity (including electrons thermal conductivity and the thermal conductivity of heavy particles) and electrical conductivity are calculated by considering the second-order approximation of Maxwell velocity distribution function, while the method of Butler et al. is adopted to calculate the reaction thermal conductivity in U-PAW. The effective value of the ultrasound velocity gradient tensor is employed to describe the effects of ultrasonic vibration on transport coefficients in ultrasound assisted plasma arc. The calculation results show that when the ultrasound is applied, the thermal conductivity of heavy particles in the plasma increases significantly and the electron thermal conductivity increases within some extent. The thermal conductivity of the reaction also increased to a great extent, and the electrical conductivity decreases a little bit. Although the thermal diffusion coefficient also has some increase, but the ordinary diffusion coefficient is obviously reduced due to the application of the ultrasound. With the updated transport coefficients, the plasma arc pressure on the anode surface is numerically computed, and the predicted pressures of PAW and U-PAW can be consistent with the measured ones.

show abstract

“…18,19 Much has been done to apply the ultrasonic and mechanic vibration during the FSW process. [20][21][22] During friction stir welding assisted by ultrasonic vibration, the welding tool or workpiece is vibrated by ultrasound waves including a low vibration amplitude (around 2-50 mm) and high vibration frequency (15-50 kHz). Zhong et al 23 investigated the ultrasonic-assisted friction stir welding (UAFSW) parameters on the temperature and material flow of aluminum joints.…”

Section: Introductionmentioning

confidence: 99%

A modified version of friction stir welding process of aluminum alloys: Analyzing the thermal treatment and wear behavior

Abdollah-zadeh

Bagheri

Abbasi

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part L:

View full text Add to dashboard Cite

In this article, the effect of vibration and cooling media on the friction stir welding of 5083Al alloy is investigated. The vibration was introduced by the motor into the fixture inserted under the workpiece while a cooling media (water and lubrication oil) flowed into a canal in the fixture beneath the weld path. A constant rotation speed of 1250 r/min and a traveling speed of 90 mm/min were used for all the welding conditions. The thermal analysis measured by several thermocouples indicated that friction stir vibration welding (FSVW) provided maximum temperature distribution in the workpiece, while friction stir welding with the water cooling exhibited the lowest temperature value. The microstructure observations were conducted by optical microscope, scanning electron microscopy, and transmission electron microscopy. The results indicated substantial grain refinement when vibration and water cooling were simultaneously applied during the friction stir welding process. The hardness values increased from 50 to around 78 (Hv) for friction stir welding and FSVW with water systems, respectively. The joint efficiency (the ratio of the joint strength to the base metal strength) of the joint fabricated by FSVW with water cooling was around 87%, while this quantity was about 66% for the friction stir welding joint. Fracture analysis indicated more ductile behaviors for the samples fabricated by FSVW with the coolant systems. Furthermore, the joint fabricated by FSVW with water cooling exhibited the best wear resistance among all the samples in a pin-on-disk wear test.

show abstract

Constitutive equation including acoustic stress work and plastic strain for modeling ultrasonic vibration assisted friction stir welding process

Cited by 48 publications

References 37 publications

Flow Stress of 6061 Aluminum Alloy at Typical Temperatures during Friction Stir Welding Based on Hot Compression Tests

Flow Stress of 6061 Aluminum Alloy at Typical Temperatures during Friction Stir Welding Based on Hot Compression Tests

Effects of Ultrasonic Vibration on the Transport Coefficients in Plasma Arc Welding

A modified version of friction stir welding process of aluminum alloys: Analyzing the thermal treatment and wear behavior

Contact Info

Product

Resources

About