scholarly journals Diffusion vacuum brazing of TiAl47 casting alloy based on TiAl (γ) intermetallic compound using Ag-Cu-Ti braze alloy

2016 ◽  
Vol 52 (04) ◽  
pp. 225-230 ◽  
Author(s):  
M. ROZANSKI ◽  
A. WINIOWSKI
Keyword(s):  
Intermetallic Compound ◽  
Braze Alloy ◽  
Casting Alloy ◽  
Vacuum Brazing

scholarly journals Vacuum Brazing Ti–15–3 with a TiNiNb Braze Alloy

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1085 ◽  
Author(s):  
Kao ◽  
Tsay ◽  
Wang ◽  
Shiue
Keyword(s):  
Intermetallic Compound ◽  
Braze Alloy ◽  
Intermetallic Phases ◽  
Brazing Fillers ◽  
Rich Phase ◽  
Ductile Dimple ◽  
Vacuum Brazing ◽  
Average Shear Strength ◽  
Average Shear ◽  
Brazed Joint

Among all types of brazing fillers, Ti-based fillers show satisfactory joint strengths in brazing titanium alloys. However, the major concern in using such fillers is the formation of Cu/Ni/Ti intermetallic compound(s) in the joint. In this study, a Ti–15–3 alloy was vacuum brazed with a clad Ti–35Ni–25Nb foil. The brazed zone consisted of a Ti2Ni intermetallic compound in a (β-Ti,Nb)-rich matrix for specimen brazing at 1000 °C/600 s. Raising brazing temperature and time resulted in the Ti2Ni dissolving into the (β-Ti,Nb)-rich matrix. For the specimen brazing at 1100 °C/600s, Ti2Ni could only be observed at the grain boundaries of the (β-Ti,Nb)-rich matrix. After further raising it to 1200 °C/600 s, the Ti2Ni intermetallic compound was all dissolved into the (β-Ti,Nb)-rich phase. The average shear strength was significantly raised from 140 (1000 °C/600 s) to 620 MPa (1100 °C/3600 s). Crack initiation/propagation in the brittle Ti2Ni compound with the cleavage fractograph were changed into the Ti–15–3 base metal with a ductile dimple fractograph. The advantage of using Nb in the TiNiNb filler foil was its ability to stabilize β-Ti, and most of the Ni in the braze alloy was dissolved into the β-Ti matrix. The brazed joint could be free of any intermetallic phases with a proper brazing cycle applied, and the joint was suitable for a few harsh applications, e.g., repeated stresses and impact loadings.

Vacuum Brazing of GH2132 Superalloy Using BNi-2+BNi-5 Composite Filler

2012 ◽  
Vol 602-604 ◽  
pp. 2087-2091
Author(s):  
Rui Feng Li ◽  
Zhi Shui Yu ◽  
Kai Qi
Keyword(s):  
Mechanical Properties ◽  
Intermetallic Compound ◽  
Intermetallic Compounds ◽  
Solution Phase ◽  
Solid Solution Phase ◽  
Vacuum Brazing ◽  
Vacuum Braze ◽  
Brazed Joint ◽  
Composite Filler ◽  
Boundary Penetration

In order to overcome the over formed intermetallic compound and the grain boundary penetration phenomenon in superalloys brazed joint using BNi-2 filler, the three variable portion of BNi2+BNi-5 composite filler is used to vacuum braze GH2132 superalloy. The results showed that the addition of BNi5 filler can decrease the formation of intermetallic compounds. For composite brazing filler of BNi2+40%BNi5, the brazing seam mainly composes of solid solution phase. The amounts of intermetallic compounds increased with the increase of brazing temperature and brazing clearance. The microhardness of the intermetallic compound is about 380~400 HV which is detrimental to the mechanical properties of the brazing joint.

Effect of Tin Content on the Microstructure and Property of Brazed WC-Co/CrMo Alloy Steel Joints

2008 ◽  
Vol 47-50 ◽  
pp. 596-599
Author(s):  
Hsin Fu Wang ◽  
Liu Ho Chiu ◽  
Heng Chang
Keyword(s):  
Shear Strength ◽  
Braze Alloy ◽  
Alloy Layer ◽  
Vacuum Brazing ◽  
Cu Alloy ◽  
Brazed Joints ◽  
Tin Content ◽  
Steel Joints ◽  
Filler Metals ◽  
Maximum Shear Strength

Vacuum brazing of Cemented Tungsten Carbide (WC-Co) and JIS SCM440 steel using Cu-Sn braze alloy has been studied. The effect of Sn content in the filler metals on the properties of brazed joints was investigated. The specimens were brazed under 1050°C to 1110°C for 5 to 15 minutes. The experimental results show that the maximum shear strength is 341±15MPa for the joints brazed at 1080°C for 10 min by using Cu-9Sn filler. Shear strength of the joints brazed at 1050°C and 1080°C increased as Sn content added to the braze alloy. However, joints brazed at 1110°C showed a decline in shear strength as the increase of Sn content. From SEM micrographs, a Fe-Co-Cu alloy layer was formed at WC-Co/Cu-Sn interface and the property of the layer was affected by brazing temperature and Sn content.

scholarly journals Vacuum Brazing of C/C Composite and TiAl Intermetallic Alloy Using BNi-2 Brazing Filler Metal

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1844
Author(s):  
Shengnan Li ◽  
Dong Du ◽  
Lei Zhang ◽  
Qingle Hao ◽  
Weimin Long
Keyword(s):  
Shear Strength ◽  
Intermetallic Compound ◽  
Filler Metal ◽  
Holding Time ◽  
Joint Shear Strength ◽  
Vacuum Brazing ◽  
Tial Intermetallic Compound ◽  
Brazed Joint ◽  
Temperature Shear ◽  
Perfect Interface

C/C composite was brazed to TiAl intermetallic compound using a commercial BNi-2 brazing filler metal under vacuum brazing condition. The brazing temperature was 1030~1150 °C and the holding time was 20 min. The joint interfacial microstructures and mechanical properties were studied, and the fracture behavior and joining mechanism were also investigated. The effect of brazing temperature on the joint shear strength was explored. The results showed that a perfect interface joint can be obtained by using BNi-2 to braze C/C and TiAl. During brazing, Ti, Cr, and other carbide forming elements diffused to C/C composite side, forming Cr3C2, Cr7C3, TiC, and other carbides, and realizing metallurgical joining between the brazing filler metal and C/C composite. The microstructure of the interface of C/C composite and TiAl intermetallic compound joint is as follows: TiAl alloy → TiAl + AlNi3 → AlNi2Ti → Ni(s, s) + Ti3Al + Ni3Si → Ni(s, s) + Ni3(Si, B) + CrB → Ni(s, s) + Ni3Si + TiCr2 → (Ti, Cr)C → C/C composite. When the holding time is fixed, with the increase of brazing temperature, the shear strength of the joint increases first and then decreases. The maximum average room temperature shear strength of the brazed joint was 11.62 MPa, while the brazing temperature was 1060 °C and the holding time was 20 min.

Vacuum Brazing Porous W and Mo Using Ti-Ni-Nb Braze Alloys

2011 ◽  
Vol 410 ◽  
pp. 187-190 ◽  
Author(s):  
C.C. Lin ◽  
Chun Chen ◽  
Ren Kae Shiue ◽  
H.J. Shy ◽  
C.Steve Chang
Keyword(s):  
Melting Point ◽  
Low Temperature ◽  
Braze Alloy ◽  
Ternary Alloys ◽  
Vacuum Brazing ◽  
Novel Approach ◽  
Ni Addition ◽  
Point Depressant ◽  
Melting Point Depressant ◽  
Filler Metals

A novel approach of brazing porous W and Mo using three clad Ti-Ni-Nb foils has been performed in the experiment. Clad Ti-Ni-Nb filler foils are featured with low brazing temperature of below 1350°C. Both W and Mo are completely soluble with β-Ti and Nb, and the Ni addition into the braze alloy is served as a melting point depressant (MPD). Decreased brazing temperature and/or time are necessary in order to minimize infiltration of the molten braze into the porous W substrate. According to the experimental results, Ti-Ni-Nb ternary alloys are promising filler metals in low-temperature brazing porous W and Mo.

scholarly journals Infrared brazing of Fe3Al intermetallic compound using gold-based braze alloy

Gold Bulletin ◽  
2011 ◽  
Vol 44 (1) ◽  
pp. 49-56
Author(s):  
Ren-Kae Shiue ◽  
Shyi-Kaan Wu ◽  
I-Hong Li
Keyword(s):  
Intermetallic Compound ◽  
Braze Alloy ◽  
Fe3al Intermetallic

Dislocation Substructures Produced During Tensile, Creep, and Fatigue Deformation of Ti3Al at 700°C

1977 ◽  
Vol 35 ◽  
pp. 272-273
Author(s):  
S. M. L. Sastry
Keyword(s):  
Intermetallic Compound ◽  
Strain Rate ◽  
Tensile Creep ◽  
Slip Systems ◽  
Slip Vector ◽  
Superlattice Structure ◽  
Slip Activity ◽  
Dislocation Arrangement ◽  
Ordered Intermetallic ◽  
Tangled Dislocation

Ti3Al is an ordered intermetallic compound having the DO19-type superlattice structure. The compound exhibits very limited ductility in tension below 700°C because of a pronounced planarity of slip and the absence of a sufficient number of independent slip systems. Significant differences in slip behavior in the compound as a result of differences in strain rate and mode of deformation are reported here.Figure 1 is a comparison of dislocation substructures in polycrystalline Ti3Al specimens deformed in tension, creep, and fatigue. Slip activity on both the basal and prism planes is observed for each mode of deformation. The dominant slip vector in unidirectional deformation is the a-type (b) = <1120>) (Fig. la). The dislocations are straight, occur for the most part in a screw orientation, and are arranged in planar bands. In contrast, the dislocation distribution in specimens crept at 700°C (Fig. lb) is characterized by a much reduced planarity of slip, a tangled dislocation arrangement instead of planar bands, and an increased incidence of nonbasal slip vectors.

Atomic structure of interface of intermetallic compound TiAl and nitride Ti2AIN using HREM and image processing

1991 ◽  
Vol 49 ◽  
pp. 570-571
Author(s):  
E. Sukedai ◽  
H. Mabuchi ◽  
H. Hashimoto ◽  
Y. Nakayama
Keyword(s):  
Mechanical Properties ◽  
Image Processing ◽  
Composite Material ◽  
Intermetallic Compound ◽  
Side Surface ◽  
High Resolution Electron Microscopy ◽  
Hexagonal Structure ◽  
Second Phase ◽  
Resolution Electron ◽  
Compound Tial

In order to improve the mechanical properties of an intermetal1ic compound TiAl, a composite material of TiAl involving a second phase Ti2AIN was prepared by a new combustion reaction method. It is found that Ti2AIN (hexagonal structure) is a rod shape as shown in Fig.1 and its side surface is almost parallel to the basal plane, and this composite material has distinguished strength at elevated temperature and considerable toughness at room temperature comparing with TiAl single phase material. Since the property of the interface of composite materials has strong influences to their mechanical properties, the structure of the interface of intermetallic compound and nitride on the areas corresponding to 2, 3 and 4 as shown in Fig.1 was investigated using high resolution electron microscopy and image processing.

Direct observation of Fe-Al-Zn ternary intermetallic compound and its transformation during the early stage of hot-dip galvanizing

1993 ◽  
Vol 51 ◽  
pp. 1116-1117
Author(s):  
C. S. Lin ◽  
W. A. Chiou ◽  
M. Meshii
Keyword(s):  
Intermetallic Compound ◽  
Reaction Rate ◽  
Diffusion Rate ◽  
Early Stage ◽  
Zinc Bath ◽  
Steel Sheets ◽  
Direct Observations ◽  
Solid Iron ◽  
Iron And Zinc ◽  
Ternary Intermetallic Compound

The galvannealed steel sheets have received ever increased attention because of their excellent post-painting corrosion resistance and good weldability. However, its powdering and flaking tendency during press forming processes strongly impairs its performance. In order to optimize the properties of galvanneal coatings, it is critical to control the reaction rate between solid iron and molten zinc.In commercial galvannealing line, aluminum is added to zinc bath to retard the diffusion rate between iron and zinc by the formation of a thin layer of Al intermetallic compound on the surface of steel at initial hot-dip galvanizing. However, the form of this compound and its transformation are still speculated. In this paper, we report the direct observations of this compound and its transformation.The specimens were prepared in a hot-dip simulator in which the steel was galvanized in the zinc bath containing 0.14 wt% of Al at a temperature of 480 °C for 5 seconds and was quenched by liquid nitrogen.

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