Diffusion Vacuum Brazing of TiAl48Cr2Nb2 Casting Alloys Based on TiAl (γ) Intermetallic Compound Using Ag-Cu-Ti Braze Alloy

2013 ◽  
Vol 211 ◽  
pp. 141-148 ◽  
Author(s):  
Maciej Różański ◽  
Krzysztof Krasnowski ◽  
Janusz Adamiec
Keyword(s):  
Titanium Alloys ◽  
Intermetallic Compounds ◽  
Filler Metal ◽  
Mechanical Test ◽  
Braze Alloy ◽  
Operational Parameters ◽  
Structural Examination ◽  
Operation Conditions ◽  
Strength Tests ◽  
Engineering Materials

Fast-developing such advanced industries as aviation, automotive and power-generation are increasing demand for new engineering materials which could resists such extreme operation conditions as high operating temperature, considerable stresses or operation in fume-affected environment. Highly desirable properties of such materials should include high hardness and strength, corrosion resistance (also when exposed to aggressive fumes) but also, first of all, low density. However such materials also requirements engineering methods to ensure obtain of good sound joints. Results in growing interest in modern engineering materials characterised by increasingly better operational parameters combined with a necessity to obtain joints of such materials representing good operation properties create important research and technological problems of today. These issues include also titanium joints or joints of titanium alloys based on intermetallic compounds. Brazing is one of the basic and sometimes even the only available welding method used for joining the aforesaid materials in production of various systems, heat exchangers and, in case of titanium alloys based on intermetallic compounds, turbine elements and space shuttle plating etc. This article presents the basic physical and chemical properties as well as the brazability of alloys based on intermetallic compounds. The work also describes the principle and mechanisms of diffusion-brazed joint formation as well as reveals the results of metallographic and strength tests involving diffusion-welded joints of TiAl48Cr2Nb2 casting alloy based on TiAl (γ) phase with the use of sandwich-type layers of silver-copper-titanium based filler metal (Ag-63%; Cu-35,5%; Ti-2%). Structural examination was performed by means of light microscopy. Furthermore, the article reveals the results of shear strength tests involving the aforementioned joints. Obtained mechanical test results of TiAl48Cr2Nb2 joints brazed with usage of three/different filler metal alloys ware compared.

Biaxial Strength Tests on Beryllium and Titanium Alloys

1974 ◽  
Author(s):  
U. S. Lindholm ◽  
L. M. Yeakley ◽  
D. L. Davidson
Keyword(s):  
Titanium Alloys ◽  
Strength Tests

Diffusion Bonding of Advanced Aerospace Metallics

1993 ◽  
Vol 314 ◽  
Author(s):  
David V. Dunford ◽  
Andrew Wisbey
Keyword(s):  
Titanium Alloys ◽  
Intermetallic Compounds ◽  
Diffusion Bonding ◽  
Metal Matrix ◽  
Aerospace Industry ◽  
Matrix Composites ◽  
Considerable Potential ◽  
Aerospace Applications ◽  
Keynote Paper ◽  
Joining Process

AbstractAdvanced aluminium and titanium alloys, metal matrix composites (MMC's) and intermetallic compounds are of considerable interest to the aerospace industry. These materials offer significant mechanical improvements over many conventional materials. Appropriate joining technologies are being developed to utilise the advantages these materials offer in aerospace applications. Diffusion bonding offers considerable potential as a joining process. This keynote paper will review diffusion bonding with reference to these advanced metallic systems.

Effect of Ruthenium, Rhenium and Yttria Additions on the Microstructure of Wide Gap Brazing of IN738

2007 ◽  
Author(s):  
Xiao Huang ◽  
Scott Yandt ◽  
Doug Nagy ◽  
Matthew Yao
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Life Cycle Cost ◽  
Filler Metal ◽  
Braze Alloy ◽  
Cost Effective ◽  
Brazed Joints ◽  
Brazed Joint ◽  
Wide Gap ◽  
Boride Phases

Modern gas and steam turbine components are subject to severe thermomechanical loads and extremely high temperature in order to provide increased performance and efficiency. Most high temperature turbine components are made of superalloys specifically developed for high temperature and high mechanical stress applications but at considerable cost. Defects may occur during manufacturing of superalloy castings as well as after service. Repair of these components, rather than replacement, helps to reduce the life cycle cost. Wide gap brazing is a cost effective and reliable means to repair gas turbine hot section components with defect sizes exceeding 0.3 mm. With proper control of the braze alloy and brazing cycle, the repaired region has been reported to posses mechanical properties approaching that of the parent materials. In order to further improve the mechanical properties of the repaired region and to explore the possibility of employing the wide gap brazing method to repair single crystal components in the future, three alloying additions, Ruthenium (Ru), Rhenium (Re) and yttria (Y2O3), were incorporated into the braze filler metal by mechanical alloying. The microstructures of the wide gap brazed joints with Ru, Re and yttria additions were studied and compared to a braze joint with standard wide gap braze alloys of IN738 and AWS BNi-9. It has been found that two types of borides formed in all braze alloys, namely eutectic γ-Ni-rich and boride phases and discrete boride containing primarily Cr and W (or Ru). The addition of Ru to the filler metal did not seem to modify the microstructural constituents after brazing. However, Ru partitioned strongly to the discrete borides. No isolated elemental Ru region was observed. On the other hand, Re addition was found to change the occurrence and distribution of both types of borides. The eutectic boride constituent was significantly reduced and finer discrete boride particles were observed. The addition of yttria did not change the boride formation but led to the generation of more voids in the brazed joint.

Solid-state joining of aluminum to titanium: A review

2021 ◽  
pp. 146442072110108
Author(s):  
Vijay S Gadakh ◽  
Vishvesh J Badheka ◽  
Amrut S Mulay
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Titanium Alloys ◽  
Intermetallic Compounds ◽  
Welding Process ◽  
High Strength ◽  
Weld Interface ◽  
Fusion Welding ◽  
Cp Ti ◽  
Welding Processes

The dissimilar material joining of aluminum and titanium alloys is recognized as a challenge due to the significant differences in the physical, chemical, and metallurgical properties of these alloys, where the increasing demands for high strength and lightweight alloys in aerospace, defense, and automotive industries. Joining these two alloys using the conventional fusion techniques produces commercially unacceptable sound joints due to irregular, complex weld pool shapes, cracking and low strength, high residual stresses, cracks, and microporosity, and the brittle intermetallic compounds formation leads to poor formability or inferior mechanical properties. The formation of intermetallic compounds is inevitable but it is less severe in solid-state than in the fusion welding process. Hence, this article reviews on aluminum–titanium joining using different solid-state and hybrid joining processes with emphasis on the effect of process parameters of the different processes on the weld microstructure, mechanical properties along with the type of intermetallic compounds and defects formed at the weld interface. Among the various solid-state welding processes for aluminum–titanium joining, the following grades of aluminum and titanium alloys were employed such as cp Ti, Ti6Al4V, cp Al, AA1xxx, AA 2xxx, AA5xxx, AA6xxx, AA7xxx, out of which Ti6Al4V and AA6xxx alloys are the most common combination.

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