Joining of Advanced and Specialty Materials XXI: Welding in the Automotive Industry / Joining, Brazing and Adhesive of Advanced Materials
Program Organizers: Mathieu Brochu, McGill University; Anming Hu, University of Tennessee; Hiroaki Mori, Osaka University; Yuri Hovanski, Brigham Young University; Darren Barborak, WeldQC inc; Akio Hirose, Osaka University; Peng He, Harbin Institute of Technology; Zhiyong Gu, University of Massachusetts Lowell; Zhenzhen Yu, Colorado School of Mines

Tuesday 2:00 PM
October 1, 2019
Room: Portland Ballroom 252
Location: Oregon Convention Center

Session Chair: Michael Halbig, NASA Glenn Research Center

2:00 PM  
A Challenge in Multi-Material Structures with Automotive Metal Fasteners: Hyun-Ju Choi1; Won-Kyung Kang1; 1Korea Automotive Technology Institute
    To meet lightweight construction for vehicle OEMs, many options have been tried out for joining/ bonding multi-material structures with either adhesives or metal fasteners. Among others, mechanical fastening or joining instead of welding is suitable for dissimilar materials. This study provides a recent overview of conventional and advanced joining techniques for multi-material thin sheets. In recent years, we have mainly focused on the dissimilar combination of UHSS[typically 22MnB5]-CFRP with SPR(self-piercing rivets) or FDS(flow drill screws) joints. To verify the suitability of these joints in aggressive environments, joint performance including salt spray testing was evaluated experimentally via tensile test using a single lap joint specimen. Microscopy techniques were used to evaluate the failures of the studied specimens as needed. Fatigue life evaluation until final failure and structural integrity assessments in the joint zone of dissimilar or multi materials mechanically fastened are introduced and discussed.

2:20 PM  
Study of Solid-State Reactions in Diffusion Bonded Inconel 600 to SiC with Metallic Interlayers: Yaiza Rodriguez1; Timothy Phero1; Allyssa Bateman1; Kyu Han1; Jim Steppan1; Balky Nair1; Brian Jaques1; 1Boise State Univ
    Bonded silicon carbide (SiC) and Inconel 600 transitions are promising structures for high temperature and high pressure heat exchanger applications. The solid-state diffusion reactions at the interfaces between SiC and Inconel 600 were studied with an Ag or Ag-Pd interlayer to optimize the bonded joints. The effects of bonding temperature, time, and pressure on diffusion behavior were investigated through scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. Characterization and tensile testing of the joints showed that the process parameters were not linearly interconnected to predict diffusion/transition behavior, and that bond strength was influenced by the quantity of new interfacial phases present. Precise control of diffusion reactions through bonding parameters dictates the feasibility and performance of the diffusion bonded SiC-Inconel 600 transitions.

2:40 PM  
Air Braze Tape for High Temperature Electrochemical Devices: Jens Darsell1; John Hardy1; Tim Lin2; Quan Yang2; Chuck Tan2; 1Pacific Northwest National Laboratory; 2Aegis Technology, Inc.
    Air brazing is a method for joining ceramics and metals used in high temperature applications such as gas separation devices and solid oxide fuel cells (SOFCs). We have previously conducted a series of high-temperature studies on the Ag-CuO system to understand its viability in creating long-lasting, oxidation resistant ceramic-ceramic and ceramic-metal joints. These studies include: an investigation of phase equilibria in the Ag–CuO system using a combination of thermal, microstructural and compositional analyses, high-temperature wetting and mechanical strength between select Ag-CuO compositions and various substrates. Our current collaboration with Aegis Technology has focused on developing an air braze tape product. In this presentation we will compare and contrast the strength of joints made with the tape product to prior results.

3:00 PM  
Investigation of Corrosion Resistance of Nickel-based Brazing Filler Metal for Stainless Steel for Heat Exchanger: Yusuke Fukai1; Ikuo Shohji1; Tetsuya Ando2; Takuya Yoshida3; Tuyoshi Kashiwase3; Noboru Otomo3; 1gunma university; 2Muroran Institute of Technology; 3Atago Mfg, Co., Ltd
    In this study, electrochemical measurement of nickel-based brazing filler metals and SUS316L stainless steel for a heat exchanger were carried out to investigate corrosion behavior of those materials. BNi-5 (Ni-Cr-Si alloy) and FP613 (Ni-Cr-Si-P alloy) filler were prepared as nickel-based brazing filler metals. Corrosion potential and polarization characteristics of BNi-5, FP613 and SUS316L were measured in a 0.06 mol/L NaCl solution at 25 ℃ and 80 ℃. Galvanic current between SUS316L and the filler metals were also measured. After the measurement, the microstructures of the specimens were observed by an electron probe micro analyzer (EPMA). As a result, it was found that BNi-5 preferentially dissolves in the SUS316L joint with BNi-5 filler, and SUS316L preferentially dissolves in the joint with FP613 filler in the NaCl solution. The EPMA analysis clarified that the Ni-rich phase preferentially dissolves in BNi-5, and the Cr and P concentrated phase preferentially dissolves in FP613.

3:20 PM  
Interfacial Reaction and Strengthening Mechanism of YIG/MTC Joint Brazed by Bismuth-based Glass: Qianqian Chen1; Peng He1; Tiesong Lin1; Panpan Lin1; Dusan Sekulic1; 1Harbin Institute of Technology
    The current investigation indicates that underlined mechanism of joining Yttrium Iron Garnet (YIG) and Magnesium Titanate Ceramic (MTC) with bismuth-based glass braze. The proposed joint design has not been investigated till present. The central hypothesis is as follows. The brazed bismuth-based glass microstructure and resulting mechanical strength of a YIG/MTC joint design support favorably a good bonding of the associated interface domains. The supporting evidence shall include (i) the bismuth-based glass would feature good wettability on YIG and MTC, (ii) the sequence of the coefficients of thermal expansions (YIG, bismuth-based glass, MTC) would be in a favorable magnitudes succession. The study reveals the interface reactions form: (i) a lamellar phase and YBO3 whiskers at the YIG/Bi25 interface, (ii) MgFe2O4, Bi4Ti3O12 whiskers and Zn2Ti3O8 reaction layer at the MTC/Bi25 interface, (iii) Fe2O3 blocky phase along the brazed seam. The mechanical integrity of joints has been studied as well.

3:40 PM  
Investigation of Mechanical Properties of Sn-5Sb and Sn-6.4Sb-3.9Ag High-temperature Lead-free Solder: Kohei Mitsui1; Ikuo Shohji1; 1Gunma University
    In this study, tensile and low fatigue properties of Sn-5Sb (mass%) and Sn-6.4Sb-3.9Ag (mass%) high-temperature lead-free solder were investigated at 25℃ and 175℃ with miniature size specimens. 0.1% proof stress and tensile strength of Sn-6.4Sb-3.9Ag are superior to those of Sn-5Sb, and elongation of Sn-6.4Sb-3.9Ag is inferior to that of Sn-5Sb at both temperatures. The fatigue life of Sn-6.4Sb-3.9Ag obeys the Manson-Coffin equation and the effect of the temperature on the fatigue life is negligible. Sn-6.4Sb-3.9Ag has superior fatigue properties compared to Sn-5Sb at 175℃. From the results of electron backscatter diffraction pattern (EBSD) analysis, it was found that the crack grows linearly at high angle grain boundaries in Sn-5Sb at 175℃. In Sn-6.4Sb-3.9Ag, the recrystallization by the dynamic recovery occurs in the larger area at 175℃ and the crack grows at complicated grain boundaries.

4:00 PM  
Joining of Additively Manufactured Titanium with Different Surface Structures and Fiber-reinforced Polyetherketone (PEK) for Lightweight Design Applications: Juliane Moritz1; Philipp Goetze2; Tom Schiefer1; Annett Klotzbach1; Elena López1; Jens Standfuss1; Frank Brueckner3; Christoph Leyens4; 1Fraunhofer Institute for Material and Beam Technology IWS; 2Technische Universitaet Dresden; 3Fraunhofer Institute for Material and Beam Technology IWS, Lulea University of Technology; 4Fraunhofer Institute for Material and Beam Technology IWS, Technische Universitaet Dresden
    Multi-material designs with tailored material properties, such as hybrid parts of metals and thermoplastics, are a key factor for implementing novel lightweight solutions, e.g. in the transportation sector. Due to the importance of sufficient adhesion between the components, the joining zone is often enlarged by applying different surface structuring methods. In this study, Ti-6Al-4V samples with different types of micron-sized surface structures were produced by electron beam melting. The obtained structures were characterized by means of optical microscopy and tactile or optical roughness measurements. Thermal direct joining was used to connect those metal samples to fiber-reinforced PEK. Moreover, titanium samples were adhesively bonded utilizing a one-component epoxy and a thermoplastic adhesive, respectively. Metallographic cross-sections of all bonded sample types were prepared. Tensile shear tests were conducted and monitored via in-situ optical strain measurements by digital image correlation. In this contribution, the high potential for lightweight applications will be discussed in-depth.

4:20 PM  
Effect of Aging under High-temperature and High-humidity Environment on Adhesion Strength and Change in Chemical Structure of Structural Adhesive: Hitomi Abiko1; Ikuo Shohji1; Seigo Shimizu2; Yugo Tomita2; 1Gunma University; 2SUBARU Co., Ltd
    The aim of this study is to investigate the effect of temperature on degradation behavior of structural adhesive for weld-bonding for automobile application under high-temperature and high-humidity environment. Lap joints of steel bonded with epoxy-based structural adhesive were aged under high temperature and high humidity conditions. After aging, shear test was conducted and the fracture mode was investigated. As a result, a linear correlation was seen between the area ratio of interfacial fracture and the adhesion strength. Degree of hydrolysis, which was investigated from the change in chemical structure observed by Fourier transform infrared spectroscopy, increases with increasing aging time and aging temperature. The effect of the surface treatment to control hydroxy group on the surface of steel on the joint strength of the lap joint was also investigated. It was found that the surface treatment can reduce the rate of deterioration of joint strength.