Advanced characterisation of microstructural evolution and liquation mechanisms in RR1000 employing a novel semi-solid testing facility

2021 ◽  
Author(s):  
◽  
Sean E. John
Keyword(s):  
Friction Welding ◽  
Rapid Heating ◽  
Propagation Rate ◽  
Weld Interface ◽  
Coarse Grain ◽  
Inertia Friction Welding ◽  
Heating Rates ◽  
Fine Grain ◽  
Testing Facility ◽  
Semi Solid

Inertia friction welding is a joining technique that is used in many industries as it can create high quality welds with narrow heat affected zones. The nickel superalloy RR1000 is routinely joined via inertia friction welding, during the manufacture of compressor components for gas turbine engines, at Rolls-Royce Plc. The conditions experienced at the weld interface of an inertia friction weld are extreme, with a combination of rapid heating rates to high temperatures and severe strain rates. These conditions are such that liquation of RR1000 is to be expected. The liquation mechanisms of two variants of RR1000 have been investigated, building on previous research, to further understand the dynamic evolution of microstructure and mechanical properties during inertia friction welding of RR1000. This investigation was accomplished by the design and commissioning of a novel semi-solid testing facility. The facility underwent numerous modifications to allow representative replication of the conditions experienced during inertia friction welding. To investigate the liquation mechanisms occurring in RR1000, fine grain and coarse grain compression specimens were heated to temperatures between 900°C and 1200°C at heating rates between 1°Cs-1 and 25°Cs-1. The fine grain and coarse grain variants were found to liquate via two mechanisms. The fine grain primarily experienced constitutional liquation of the primary γ’ precipitates, while incipient melting of the γ phase was experienced by the coarse grain variant. The liquid propagation rate in both variants was characterised. The knowledge and understanding gained via the use of this facility was then applied to analyse the microstructures from a series of interrupted RR1000 inertia friction welds. Inspection of these interrupted welds revealed evidence of liquation like that observed in the specimens tested in the semi-solid testing facility. This research has given an insight into the role of liquation during inertia friction welding of RR1000.

The Evaluation of Coefficient of Friction for Representative and Predictive Finite Element Modelling of the Inertia Friction Welding

2009 ◽  
Author(s):  
M. B. Mohammed ◽  
C. J. Bennett ◽  
T. H. Hyde ◽  
E. J. Williams
Keyword(s):  
Finite Element ◽  
Coefficient Of Friction ◽  
Friction Welding ◽  
Mechanical Energy ◽  
Rotational Velocity ◽  
Welding Process ◽  
High Strength ◽  
Weld Interface ◽  
Inertia Friction Welding ◽  
Finite Element Software

Inertia friction welding is the process in which stored kinetic energy in a flywheel is converted to heat by relative sliding movement between surfaces of axi-symmetric components to achieve a weld in the solid-state. The work in this paper relates to the production of dual-alloy shafts for aeroengines. Frictional characteristics determine the conditions at the weld interface and these are controlled by rotational velocity and applied axial pressure. So-called representative and predictive methods have been developed to evaluate friction conditions during the process and these are discussed in this paper. Weld data for the dissimilar weld between a high strength steel and a nickel-based super-alloy were provided by Rolls-Royce and MTU Aero Engines. The finite element software package DEFORM-2D is used to develop coupled thermo-mechanical axi-symmetric models. In previous work, methods employed to evaluate the efficiency of mechanical energy utilised during a weld, a parameter of great importance for numerical analysis, are not clear. Previous predictive approaches have employed test/weld data in one way or another to obtain the interface friction coefficient. This paper proposes a formula that incorporates the value of the mechanical energy efficiency of the welding machine into the calculation of coefficient of friction for representative modelling. It also introduces a predictive approach based on sub-layer flow theory to predict frictional behaviour during the welding process that is independent of test/weld data.

Thermal and mechanical induced texture evolution of inertia friction welding in α + β titanium alloy

2020 ◽  
Vol 277 ◽  
pp. 128329 ◽  
Author(s):  
Y.H. Liu ◽  
Z.B. Zhao ◽  
C.B. Zhang ◽  
Q.J. Wang ◽  
H. Sun ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Friction Welding ◽  
Texture Evolution ◽  
Inertia Friction Welding

Efficiency of the Inertia Friction Welding Process and Its Dependence on Process Parameters

2017 ◽  
Vol 48 (7) ◽  
pp. 3328-3342 ◽  
Author(s):  
O. N. Senkov ◽  
D. W. Mahaffey ◽  
D. J. Tung ◽  
W. Zhang ◽  
S. L. Semiatin
Keyword(s):  
Process Parameters ◽  
Friction Welding ◽  
Welding Process ◽  
Inertia Friction Welding

scholarly journals Microstructure and Mechanical Properties of Dissimilar Friction Welding Ti-6Al-4V Alloy to Nitinol

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 109
Author(s):  
Ateekh Ur Rehman ◽  
Nagumothu Kishore Babu ◽  
Mahesh Kumar Talari ◽  
Yusuf Siraj Usmani ◽  
Hisham Al-Khalefah
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Flow Stress ◽  
Intermetallic Compound ◽  
Ultimate Tensile Strength ◽  
Friction Welding ◽  
Welding Process ◽  
Weld Interface ◽  
Dissimilar Joints ◽  
Dissimilar Alloys

In the present study, a friction welding process was adopted to join dissimilar alloys of Ti-Al-4V to Nitinol. The effect of friction welding on the evolution of welded macro and microstructures and their hardnesses and tensile properties were studied and discussed in detail. The macrostructure of Ti-6Al-4V and Nitinol dissimilar joints revealed flash formation on the Ti-6Al-4V side due to a reduction in flow stress at high temperatures during friction welding. The optical microstructures revealed fine grains near the Ti-6Al-4V interface due to dynamic recrystallization and strain hardening effects. In contrast, the area nearer to the nitinol interface did not show any grain refinement. This study reveals that the formation of an intermetallic compound (Ti2Ni) at the weld interface resulted in poor ultimate tensile strength (UTS) and elongation values. All tensile specimens failed at the weld interface due to the formation of intermetallic compounds.

Probing boron thermite energy release at rapid heating rates

2021 ◽  
Vol 231 ◽  
pp. 111491
Author(s):  
Jennifer L. Gottfried ◽  
Elliot R. Wainwright ◽  
Sidi Huang ◽  
Yue Jiang ◽  
Xiaolin Zheng
Keyword(s):  
Energy Release ◽  
Rapid Heating ◽  
Heating Rates

METALLURGICAL AND CORROSION CHARACTERIZATION OF POST WELD HEAT TREATED DUPLEX STAINLESS STEEL (UNS S31803) JOINTS BY FRICTION WELDING PROCESS

2016 ◽  
Vol 23 (03) ◽  
pp. 1650013 ◽  
Author(s):  
MOHAMMED ASIF M. ◽  
KULKARNI ANUP SHRIKRISHNA ◽  
P. SATHIYA
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Friction Welding ◽  
Volume Fraction ◽  
Welding Process ◽  
Equilibrium Temperature ◽  
Weld Interface ◽  
Heat Treated ◽  
Weld Heat

The present study focuses on the metallurgical and corrosion characterization of post weld heat treated duplex stainless steel joints. After friction welding, it was confirmed that there is an increase in ferrite content at weld interface due to dynamic recrystallization. This caused the weldments prone to pitting corrosion attack. Hence the post weld heat treatments were performed at three temperatures 1080[Formula: see text]C, 1150[Formula: see text]C and 1200[Formula: see text]C with 15[Formula: see text]min of aging time. This was followed by water and oil quenching. The volume fraction of ferrite to austenite ratio was balanced and highest pit nucleation resistance were achieved after PWHT at 1080[Formula: see text]C followed by water quench and at 1150[Formula: see text]C followed by oil quench. This had happened exactly at parameter set containing heating pressure (HP):40 heating time (HT):4 upsetting pressure (UP):80 upsetting time (UP):2 (experiment no. 5). Dual phase presence and absence of precipitates were conformed through TEM which follow Kurdjumov–Sachs relationship. PREN of ferrite was decreasing with increase in temperature and that of austenite increased. The equilibrium temperature for water quenching was around 1100[Formula: see text]C and that for oil quenching was around 1140[Formula: see text]C. The pit depths were found to be in the range of 100[Formula: see text]nm and width of 1.5–2[Formula: see text][Formula: see text]m.

Analysis of Cracking Process in Conditions of High-Temperature Creep of Castings Form the Modified Superalloy IN-713C

2013 ◽  
Vol 212 ◽  
pp. 247-254
Author(s):  
Marek Cieśla ◽  
Franciszek Binczyk ◽  
Marcin Mańka
Keyword(s):  
High Temperature ◽  
Creep Resistance ◽  
Nickel Superalloy ◽  
Morphological Properties ◽  
Coarse Grain ◽  
High Temperature Creep ◽  
Temperature Creep ◽  
Fine Grain ◽  
Initiation And Propagation ◽  
Cracking Process

mpact of complex modification and filtration during pouring into moulds on durability has been evaluated in this study in conditions of high-temperature creep of castings made from nickel superalloy IN-713C post production rejects. The conditions of initiation and propagation of cracks in the specimens were analysed with consideration of morphological properties of material macro-, micro-and substructure. It has been demonstrated that in conditions of high-temperature creep at temperature 980°C with stress σ =150 MPa creep resistance of the IN-713C superalloy increases significantly with the increase of macrograin size. Creep resistance of specimens made of coarse grain material was significantly higher than the resistance of fine grain material.

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