On intermetallic phases formed during interdiffusion between aluminium alloys and stainless steel

2D and especially 3D symmetry information required to determine the crystal structure of four intermetallic phases present as small particles (average size in the range 100-500nm) in a Fe.22Cr.5Ni.3Mo.0.03C duplex stainless steel is not present in most Convergent Beam Electron Diffraction (CBED) patterns. Nevertheless it is possible to deduce many crystal features and to identify unambiguously these four phases by means of microdiffraction patterns obtained with a nearly parallel beam focused on a very small area (50-100nm).From examinations of the whole pattern reduced (RS) and full (FS) symmetries the 7 crystal systems and the 11 Laue classes are distinguished without ambiguity (1). By considering the shifts and the periodicity differences between the ZOLZ and FOLZ reflection nets on specific Zone Axis Patterns (ZAP) which depend on the crystal system, the centering type of the cell and the glide planes are simultaneously identified (2). This identification is easily done by comparisons with the corresponding simulated diffraction patterns.

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Joining of SiO2 glass and 316L stainless steel using Bi–Ag-based active solders

Journal of Materials Science ◽

10.1007/s10853-020-05426-4 ◽

2020 ◽

Vol 56 (4) ◽

pp. 3444-3454

Author(s):

Felix Weber ◽

Markus Rettenmayr

Keyword(s):

Stainless Steel ◽

Cross Sections ◽

316L Stainless Steel ◽

Dissimilar Materials ◽

Intermetallic Phases ◽

Reaction Products ◽

Cast State ◽

Metallic Component ◽

X Ray ◽

Solder Interface

Abstract Active brazing is a commonly used method for joining dissimilar materials with at least one non-metallic component. In the present study, joining of SiO2 glass to 316L stainless steel was performed utilizing Bi–Ag-based solders. Ti up to a concentration of 4 and Mg up to 1 wt.% were added as active elements. Microstructures of the solder alloys in the as-cast state and of cross sections of the joined compounds were analysed using scanning electron microscopy and energy-dispersive X-ray spectroscopy. In the as-cast state of the solder, Ti is found in Bi–Ti intermetallic phases; Mg is partially dissolved in the fcc-(Ag) phase and additionally contained in a ternary Ag-Bi-Mg phase. After soldering, a tight joint was generated using several alloy compositions. Ti leads to the formation of reaction products at the steel/solder and glass/solder interfaces, and Mg is exclusively accumulated at the glass/solder interface.

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A Review on Diffusion Bonding between Titanium Alloys and Stainless Steels

Advances in Materials Science and Engineering ◽

10.1155/2018/8701890 ◽

2018 ◽

Vol 2018 ◽

pp. 1-15 ◽

Cited By ~ 15

Author(s):

De-feng Mo ◽

Ting-feng Song ◽

Yong-jian Fang ◽

Xiao-song Jiang ◽

Charles Q. Luo ◽

...

Keyword(s):

Mechanical Properties ◽

Stainless Steel ◽

Titanium Alloy ◽

Titanium Alloys ◽

Stainless Steels ◽

Diffusion Bonding ◽

Low Cost ◽

Phase Interface ◽

Intermetallic Phases ◽

Voids Growth

High-quality joints between titanium alloys and stainless steels have found applications for nuclear, petrochemical, cryogenic, and aerospace industries due to their relatively low cost, lightweight, high corrosion resistance, and appreciable mechanical properties. This article reviews diffusion bonding between titanium alloys and stainless steels with or without interlayers. For diffusion bonding of a titanium alloy and a stainless steel without an interlayer, the optimized temperature is in the range of 800–950°C for a period of 60–120 min. Sound joint can be obtained, but brittle FeTi and Fe-Cr-Ti phases are formed at the interface. The development process of a joint mainly includes three steps: matching surface closure, growth of brittle intermetallic compounds, and formation of the Kirkendall voids. Growth kinetics of interfacial phases needs further clarification in terms of growth velocity of the reacting layer, moving speed of the phase interface, and the order for a new phase appears. The influence of Cu, Ni (or nickel alloy), and Ag interlayers on the microstructures and mechanical properties of the joints is systematically summarized. The content of FeTi and Fe-Cr-Ti phases at the interface can be declined significantly by the addition of an interlayer. Application of multi-interlayer well prevents the formation of intermetallic phases by forming solid solution at the interface, and parameters can be predicted by using a parabolic diffusion law. The selection of multi-interlayer was done based on two principles: no formation of brittle intermetallic phases and transitional physical properties between titanium alloy and stainless steel.

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Development of an Extraction Replica Technique for the Analysis of Intermetallic Phases in Aluminium Alloys / Entwicklung eines Ausziehabdruckverfahrens für die Analyse von intermetallischen Phasen in Aluminiumlegierungen

Practical Metallography ◽

10.1515/pm-1986-231003 ◽

1986 ◽

Vol 23 (10) ◽

pp. 485-492

Author(s):

Jan Strid ◽

Christian J. Simensen

Keyword(s):

Aluminium Alloys ◽

Intermetallic Phases ◽

Replica Technique ◽

Extraction Replica

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The Failure Degradation of Recycled Aluminium Alloys with High Content of β-Al5FeSi Intermetallic Phases

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.403.97 ◽

2020 ◽

Vol 403 ◽

pp. 97-102

Author(s):

Denisa Medvecká ◽

Lenka Kuchariková ◽

Milan Uhríčik

Keyword(s):

Aluminium Alloys ◽

Cast Alloy ◽

Intermetallic Phases ◽

X Ray ◽

Fracture Surfaces ◽

Phase Lead ◽

Micro Cracks ◽

Fe Content ◽

Increased Risk ◽

Cast Alloys

In this study, the effect of the β-Al5FeSi phases on fracture surfaces in secondary AlSi7Mg0.3 cast alloys with common and higher amount of iron was investigated. Iron addition caused the formation of different Fe-rich intermetallic phases in aluminium alloys. Components made of secondary aluminium alloys commonly have a higher amount of such phases. Sharp needles as β-Al5FeSi phase lead to initiate stress tension, thereby contributing to increased risk of micro-cracks formation on the fracture surfaces. To determine the effect of β-Al5FeSi to fracture surfaces of AlSi7Mg0.3 cast alloy, SEM microscopy with energy-dispersive X-ray spectroscopy (EDX) was used to study the amount of needles phases, their morphology and violation wave. It was found that increasing Fe content increased the size and the number of Al5FeSi phases. The fractographic analysis of fracture surfaces shows an increasing amount of cleavage fracture in materials with a higher amount of iron, too.

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