Wettability Of High Temperature Materials During Transient Liquid Phase Tlp Bonding

The purpose of this book is to bring together current scientific understanding of wetting behaviour that has been gained from theoretical models and quantitative experimental observations. The materials considered are liquid metals or inorganic glasses in contact with solid metals or ceramics at temperatures of 200-2000oC. Wetting has been a significant scientific concern for the last two centuries and reference will be made to classical work by nineteenth century scientists such as Dupré, Laplace and Young that was validated by observations of the behaviour of chemically inert ambient temperature systems.In attempting to achieve the aims of the book, the text has been divided into ten Chapters that can be grouped into four stages of presentation. The first stage comprises two Chapters that review established and newly developed models for their relevance to wetting behaviour at high temperatures, including recent models that encompass the role of chemical reactions at the solid/liquid interfaces. Attention is paid both to equilibrium wetting behaviour (Chapter 1) and to the factors that control the approach to equilibrium (Chapter 2). Then follow Chapters concerned with experimental techniques for scientific measurement of the extent of wetting (Chapter 3) and with the surface energy data for both metals and non-metals that are essential for quantitative interpretation of wetting behaviour (Chapter 4). Descriptions of experimentally determined and quantified wetting behaviour are presented and interpreted in the third part comprising five Chapters dealing with the characteristics of metal/metal, metal/oxide, metal/non-oxide, metal/carbon and molten glass/solid systems. The book concludes with a Chapter commenting on the role of wetting behaviour in joining similar and dissimilar materials by liquid route techniques.

The book presents a complete overview on the topic of Transient Liquid Phase Bonding (TLPB) which has many high-tech applications, ranging from the production and repair of turbine engines in the aerospace industry, to nuclear power plants and the connection of circuit lines in the microelectronics industry. The TLPB process and its specific applications are presented in great detail: Self-Bonding of Pure Materials; Bonding Different Pure Materials; Self-Bonding of Composites; Self-Bonding of Simple Alloys; Self-Bonding of Complex Alloys; Bonding Same-Base Alloys; Bonding Different-Base Alloys; Bonding Ceramics to Ceramics; Bonding Ceramics to Metals. The book references 483 original resources and includes their direct web link for in-depth reading.

Transient liquid phase (TLP) bonding has become a very attractive method of joining similar and dissimilar difficult-to-weld advanced materials. The effects of process parameters on the joint microstructure of TLP bonded nickel-based superalloy IN738 and cobalt metal using Nicrobraz 150 interlayer are investigated in this research. It is discovered that adequate processing time (tf) is required to prevent formation of deleterious eutectic that is known to degrade the mechanical properties of the joint. Increase in temperature to a certain point reduces the size of the eutectic in the joint due to increase in diffusivity with increase in temperature. However, a further increase in temperature above this temperature produced a larger width of the eutectic at the joint because of the overriding effect of solubility on diffusivity at higher temperatures. The eutectic in dissimilar IN 738/Co is asymmetrically distributed within the joint and this is caused by liquid-state diffusion, which has been generally ignored in the discussion of TLP bonding of dissimilar materials in the literature. In contrast to the expectation that rapid atomic diffusion in the liquid would reduce the processing time (tf) required to completely eliminate the eutectic from the joint region through diffusional solidification, the occurrence of liquid-state diffusion significantly prolonged the processing time. This requires adequate consideration in the use of TLP bonding for joining dissimilar materials.

This book presents peer reviewed articles from the Green Materials and Electronic Packaging Interconnect Technology Symposium, (EPITS 2022), held in Langkawi, Malaysia on 14th and 15th of Sept, 2022. It brings together packaging experts to share and exchange ideas in electronics technology. Topics covered in this volume include, but are not limited to; (1) Green materials and technology, (2) Emerging interconnect materials and technologies,(3) Non-solder interconnect materials at chip and package levels, (4) Fundamental materials behavior for electronic packaging materials, (5) Advanced characterization methods as applied to electronic packaging technology, (6) Developments in high temperature Pb-free solders and associated interconnects for automotive and power electronics, (7) Surface coating materials & (8) Advanced materials. ​

This volume, titled Proceedings of the International Materials Symposium on Ce ramic Microstructures: Control at the Atomic Level summarizes the progress that has been achieved during the past decade in understanding and controlling microstructures in ceram ics. A particular emphasis of the symposium, and therefore of this volume, is advances in the characterization, understanding, and control of micro structures at the atomic or near-atomic level. This symposium is the fourth in a series of meetings, held every ten years, devoted to ceramic microstructures. The inaugural meeting took place in 1966, and focussed on the analysis, significance, and production of microstructure; the symposium emphasized the need for, and importance of characterization in achieving a more complete understanding of the physical and chemical characteristics of ceramics. A consensus emerged at that meeting on the critical importance of characterization in achieving a more complete understanding of ceramic properties. That point of view became widely accepted in the ensuing decade. The second meeting took place in 1976 at a time of world-wide energy shortages and thus emphasized energy-related applications of ceramics, and more specifically, microstructure-property relationships of those materials. The third meeting, held in 1986, was devoted to the role that interfaces played both during processing, and in influencing the ultimate properties of single and polyphase ceramics, and ceramic-metal systems.

The suitability of using transient liquid phase (TLP) bonding to fabricate honeycomb core sandwich panels with Ti-14Al-21Nb (wt%) titanium aluminide (T3Al) face sheets for high-temperature hypersonic vehicle applications was evaluated. Three titanium alloy honeycomb cores and one Ti3Al alloy honeycomb core were investigated. Edgewise compression (EWC) and flatwise tension (FWT) tests on honeycomb core sandwich specimens and tensile tests of the face sheet material were conducted at temperatures ranging from room temperature to 1500 F. EWC tests indicated that the honeycomb cores and diffusion bonded joints were able to stabilize the face sheets up to and beyond the face sheet compressive yield strength for all temperatures investigated. The specimens with the T3Al honeycomb core produced the highest FWT strengths at temperatures above 1000 F. Tensile tests indicated that TLP processing conditions resulted in decreases in ductility of the Ti-14Al-21Nb face sheets. Microstructural examination showed that the side of the face sheets to which the filler metals had been applied was transformed from equiaxed alpha2 grains to coarse plates of alpha2 with intergranular Beta. Fractographic examination of the tensile specimens showed that this transformed region was dominated by brittle fracture. Bird, R. Keith and Hoffman, Eric K. Langley Research Center RTOP 522-12-11-01...