Solid State Diffusion Bonding of Metals and Alloys: Solid State Diffusion Bonding of Metals and Alloys II
Sponsored by: TMS Materials Processing and Manufacturing Division, TMS: Advanced Characterization, Testing, and Simulation Committee
Program Organizers: Mohamed Elbakhshwan, University of Wisconsin Madison; Mark Anderson, University of Wisconsin Madison; Todd Allen, University of Michigan ; Tasnim Hassan, North Carolina State University
Monday 2:30 PM
February 24, 2020
Room: 19
Location: San Diego Convention Ctr
Session Chair: Tasnim Hassan, North Carolina State University; Heramb Heramb Mahajan , North Carolina State University
2:30 PM Invited
Tensile Performance of Diffusion Bonded Haynes 230 Alloy for use in a Compact Heat Exchanger: Kyle Rozman1; W. Pratte2; Thaddeus Rahn2; Brian Fronk2; Brian Paul2; Ömer Doğan1; 1National Energy Technology Laboratory; 2Oregon State University
Advancing manufacturing and engineering technology of microchannel heat exchangers has been identified as one of the most critical aspects of the Brayton cycle, utilizing supercritical CO2 above 700oC and 8 MPa. This project investigates the ability of Haynes 230 to be used in microchannel heat exchangers. Diffusion bonding offers tight dimension tolerances, which is critical to the manufacturing of heat exchangers, while selection of Haynes 230 offers excellent corrosion resistance and creep resistance at elevated temperatures. Stacks of Haynes 230 sheets, 0.5 mm thick, were diffusion bonded together to assess the mechanical properties of the diffusion bond. Mechanical properties of the bond are discussed.
3:00 PM
Anisotropic Grain Growth in Cu Joints at Low Temperatures by <111>-oriented Nanotwinned Copper Films: Chang-Chih Hsieh1; Chih Chen1; 1National Chiao Tung University
Grain growth in Cu joints can eliminate the bonding interface and ensure good bonding strength, and hence increase the reliabilities for the Cu-to-Cu joints, such as resistance to temperature cycling tests. However, grain growth takes place at temperature higher than 300 °C in regular Cu joints.In this study, we reduce the temperature for grain growth of Cu joints at 225 °C using highly (111)-oriented nanotwinned Cu (nt-Cu) films. We electrodeposited nt-Cu films with periodic reverse waveform rather than DC waveform. Then We bonded two pieces of nt-Cu films at 225 °C under 114 psi(0.78MPa) for 120 min at 10-3 torr. The microstructure analysis indicates that extremely anisotropic grain growth can be triggered at this conditions. This temperature is the lowest one that has been reported for the elimination of the bonding interface of Cu-to-Cu joints.
3:20 PM
Microstructural Characterizations and Mechanical Properties of Diffusion Bonded Stainless Steel 316H and Inconel 800H: Mohamed Elbakhshwan1; Ian Jentz1; Collin Magnin1; Andrew Brittan2; Mark Anderson1; Todd Allen3; 1University of Wisconsin, Madison; 2Oregon State University; 3University of Michigan
Advancements in manufacturing processes have resulted in significant improvements in heat exchanger technology. Compact heat exchangers (CHXs) are developed for efficient transferring of heat with low space and weight requirements, high thermal effectiveness, low-pressure drop, and moderate to high design pressure capability. Solid state diffusion bonding is an essential process used in the manufacture of CHXs in many industries. In this study we will discuss the microstructural characterizations and mechanical properties of diffusion bonded joints of high temperature alloys: Stainless Steel 316H and Inconel 800H. Post-bonding characterizations revealed several microstructural changes in the alloys such as grain diffusion across the bonding line, grain growth in regions attached to the bonding line, and diffusion of the interdiffusion layers. These changes force the bonded region to have different microstructure and mechanical response compared to the parent alloy. Therefore, correlations between the microstructure and alloy strength and creep resistance will be discussed.
3:40 PM
Microstructure Evolution and Mechanical Properties of Diffusion Bonded Ti6Al4V Alloy Joints for Aerospace Applications: Rajakumar S1; Pragatheswaran T1; Kavitha S1; Balasubramanian V1; Vijay Petley2; Shweta Verma2; 1Annamalai University; 2Gas Turbine Research Establishment (GTRE)
Utilization of titanium alloys in the aero-engine industries is increased due their unique characteristics. Joining Ti alloys require more sophisticated technique like diffusion bonding process which is a solid state process and it is able to provide good quality joints without drastic modification in the microstructure of the material. In this research work, thin sheets of Ti alloy Ti6Al4V having a thickness of 2 mm are diffusion bonded with the aim of analyzing the role of transformation temperature during diffusion bonding and its effects on microstructure evolution and mechanical properties. The results showed that interdiffusion of elements increases with increase in bonding temperature. The growth of lamellar α and β phases increases with increase in bonding temperature. The diffusion bonds produced from a bonding temperature above α-β transformation temperature exhibits more equiaxed α and β rich coarser grain with high shear strength and hardness. Keywords: Diffusion, Titanium, Tensile, Microstructure, Hardness
4:00 PM Break
4:30 PM
Modeling Strength of Diffusion Bonded Interface Using Phase-Field Recrystallization and Creep-Damage Models.: Aritra Chakraborty1; Andrea Rovinelli1; Mark Messner1; T.L. Sham1; 1Argonne National Laboratory
Diffusion bonding is a promising alternative to other welding techniques for joining of high-strength refractory materials that are frequently used in aerospace and nuclear industries, because of the low residual stresses developing at the joined interface and excellent oxidation resistance. Since the process generally operates at elevated temperatures and pressure (stresses), it leads to dynamic recrystallization at the bonded interface, which can then significantly affect the strength of the bonded material. In this work, the process of dynamic recrystallization at this bonded interface is modeled using phase-field modeling implemented in the multi-physics software MOOSE. Following the phase-field simulations, the creep strength of the interface resulting from the diffusion bonding process is analyzed via crystal plasticity simulations. The effect of grain boundary cavitation damage is included in the simulations utilizing a discontinuous Galerkin cohesive zone approach. Results show the importance of the interface microstructure to achieve the optimal interface strength.
4:50 PM
Solid-state Diffusion Bonding of Glass-metal for the International Thermonuclear Experimental Reactor (ITER) Diagnostic Windows: Lee Aucott1; 1United Kingdom Atomic Energy Authority
The United Kingdom Atomic Energy Authority are involved in the design and manufacture of the diagnostic windows for ITER. ITER is an international project, with 35 nations collaborating to design, construct and operate a prototype controlled nuclear fusion reactor in southern France. As well as providing line of sight for diagnostics, the windows also form part of the reactor primary containment boundary and are consequently classified as nuclear Safety Important Class 1 (SIC-1) components. The windows will be the first SIC-1 components in the world which are non-metallic. The current manufacturing process involves diffusion bonding a glass window to an Inconel 625 ferrule via an aluminium interlayer. This report discusses this diffusion bonding process and details the specific challenges related to component qualification for the intended nuclear SIC-1 application.
5:10 PM
Solid State Joining of Dissimilar Ni-based Superalloys Using Field Assisted Sintering Technology: Charis Lin1; Namiko Yamamoto1; Derek King2; Jogender Singh1; 1The Pennsylvania State University; 2UES Inc.
Turbine disks are currently made of nickel-based superalloys, known for their high strength and creep resistance at high temperatures. Dual-microstructure turbine disks allow for significant weight-savings, but current methods of joining dissimilar nickel-based superalloys such as friction welding exhibit a heat affected zone and localized melting at the interface, leading to weak bonding. Here, we study Field Assisted Sintering Technology as a novel method to sinter the nickel-based superalloy powder CM247LC to high relative density. In addition, the sintered CM247LC material was joined with Inconel 718 using FAST as a solid state joining method. Our preliminary results indicate that the bond between the two superalloys has a similar tensile strength to the base Inconel 718 material.