scholarly journals Computational modelling of dynamic recrystallisation of Ni-based superalloy during linear friction welding

2022 ◽  
Author(s):  
Saviour I. Okeke ◽  
Noel M. Harrison ◽  
Mingming Tong
Keyword(s):  
Grain Size ◽  
Friction Welding ◽  
Computational Modelling ◽  
Process Parameter ◽  
Process Window ◽  
Linear Friction Welding ◽  
Joining Technology ◽  
Friction Pressure ◽  
Linear Friction ◽  
Dynamic Recrystallisation

AbstractLinear friction welding (LFW) is an advanced joining technology used for manufacturing and repairing complex assemblies like blade integrated disks (blisks) of aeroengines. This paper presents an integrated multiphysics computational modelling for predicting the thermomechanical-microstructural processes of IN718 alloy (at the component-scale) during LFW. Johnson–Mehl–Avrami-Kolmogorov (JMAK) model was implemented for predicting the dynamic recrystallisation of γ grain, which was coupled with thermomechanical modelling of the LFW process. The computational modelling results of this paper agree well with experimental results from the literature in terms of γ grain size and weld temperature. Twenty different LFW process parameter configurations were systematically analysed in the computations by using the integrated model. It was found that friction pressure was the most influential process parameter, which significantly affected the dynamic recrystallisation of γ grains and weld temperature during LFW. The integrated multiphysics computational modelling was employed to find the appropriate process window of IN718 LFW.

scholarly journals Dissolution of delta phase in Ni-based superalloy during linear friction welding: integrated multiphysics computational process modelling

2021 ◽  
Author(s):  
Saviour I. Okeke ◽  
Noel M. Harrison ◽  
Mingming Tong
Keyword(s):  
Microstructural Evolution ◽  
Friction Welding ◽  
Volume Fraction ◽  
Computational Modelling ◽  
Process Parameter ◽  
Linear Friction Welding ◽  
Influence Of Process Parameters ◽  
Phase Volume Fraction ◽  
Linear Friction ◽  
Δ Phase

AbstractLinear friction welding (LFW) is an increasingly popular solid-state joining method for challenging applications such as integrated blade disk of aero-engines. However, the influence of friction-generated heat on the material microstructural evolution, material deformation and resultant mechanical performance of the manufactured components is not well understood. A novel integrated multiphysics computational modelling is presented for predicting the component-scale microstructural evolution of IN718 alloy during LFW. A modified time-temperature equivalence formulation was implemented for predicting the evolution of the δ phase, which was coupled with thermomechanical modelling of the LFW process. There is reasonably good agreement between the computational modelling results of this paper and the experimental results from the literature in terms of δ phase volume fraction and weld temperature. The integrated multiphysics computational modelling predicts the influence of process parameters on thermomechanical and microstructural processes of IN718 LFW. By systematically analysing the influence of 10 different LFW process parameter configurations, the friction pressure was identified as the most influential process parameter determining the extent of δ phase dissolution and weld temperature during LFW.

Thermomechanical modelling for the linear friction welding process of Ni-based superalloy and verification

2020 ◽  
Vol 234 (5) ◽  
pp. 796-815
Author(s):  
SI Okeke ◽  
N Harrison ◽  
M Tong
Keyword(s):  
Melting Temperature ◽  
Process Parameters ◽  
Friction Welding ◽  
Inconel 718 ◽  
Computational Modelling ◽  
Welding Process ◽  
Model Verification ◽  
Linear Friction Welding ◽  
Inconel 718 Alloy ◽  
Linear Friction

This paper presents a fully coupled thermomechanical model for the linear friction welding process of Inconel-718 nickel-based superalloy by using the finite element method. Friction heat, plastic work, and contact formulation were taken into account for two deformable plastic bodies oscillating relative to each other under large compressive force. The modelling results of the thermal history at the weldline interface and thermal field at a distance away from the rubbing surfaces were compared to instrumented data sourced from related publications for model verification. Optimal linear friction welding process parameters were identified via comparison of weld temperature to the liquidus temperature of Inconel-718 alloy. Comparison of interface temperature showed a consistent range of values above the solidus melting temperature (1250 ℃) and below the liquidus melting temperature (1360 ℃) of Inconel-718 alloy. For the first time, a visible linear friction welding process window is identified using a thermomechanical computational modelling method. Through computational modelling, the influence of welding process parameters on the heat transfer and deformation of weld was systematically investigated.

scholarly journals Characterisation of Microstructure and Mechanical Properties of Linear Friction Welded α+β Titanium Alloy to Nitinol

2021 ◽  
Vol 11 (22) ◽  
pp. 10680
Author(s):  
Ateekh Ur Rehman ◽  
Nagumothu Kishore Babu ◽  
Mahesh Kumar Talari ◽  
Yusuf Usmani ◽  
Hisham Alkhalefah
Keyword(s):  
Friction Welding ◽  
Welding Process ◽  
Fusion Welding ◽  
Linear Friction Welding ◽  
Flow Strength ◽  
Turbofan Engine ◽  
Aircraft Fuel ◽  
Linear Friction ◽  
Dynamic Recrystallisation ◽  
Bypass Ratio

A variable area nozzle integrated into the design of a high-bypass-ratio turbofan engine effectively saves up to 10% in aircraft fuel consumption. Additionally, noise emissions can be lowered at airports during take-off and landing by having better control of the nozzle diameter. Shape memory capabilities of Nitinol alloys could be availed in the form of actuators in the construction of such a nozzle. However, these Nitinol actuators must be joined to Ti-6Al-4V, a prominent alloy making up most of the rest of the nozzle. Because of the huge differences in the physical and metallurgical properties of these alloys, fusion welding is not as effective as solid-state welding. In the current study, a linear friction welding process was adopted to join Ti-6Al-4V to Nitinol successfully. The effect of friction welding on the evolution of weld macro and microstructures; hardness and tensile properties were studied and discussed. The macrostructure of Ti-6Al-4V and Nitinol’s dissimilar joint revealed flash formation mainly on the Ti-6Al-4V side due to its reduced flow strength at high temperatures. Optical microstructures revealed fine grains in Ti-6Al-4V immediately adjacent to the interface due to dynamic recrystallisation and strain hardening effects. In contrast, Nitinol remained mostly unaffected. An intermetallic compound (Ti2Ni) was seen to have formed at the interface due to the extreme rubbing action, and these adversely influenced the tensile strength and elongation values of the joints.

Effect of Process Parameters on Welding Variables during Linear Friction Welding of Ti-6Al-4V Alloy

2011 ◽  
Vol 314-316 ◽  
pp. 979-983
Author(s):  
Tie Jun Ma ◽  
Xi Chen ◽  
Wen Ya Li
Keyword(s):  
Titanium Alloy ◽  
Process Parameters ◽  
Friction Welding ◽  
Welding Process ◽  
Orthogonal Experimental Design ◽  
Linear Friction Welding ◽  
Influence Of Process Parameters ◽  
Linear Friction ◽  
Suitable Process ◽  
Axial Shortening

The orthogonal experimental design was conducted for linear friction welding of Ti-6Al-4V titanium alloy (TC4). The friction power and joint temperature were collected during the welding process. The influence of process parameters on the axial shortening was analyzed. The suitable process parameters were determined by investigating the joint appearance, the requirement of axial shortening and welding variables during welding. The results provide important reference for establishing process parameters of linear friction welding in practice.

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