scholarly journals Joining of Hypereutectic Al-50Si Alloys Using Lead-Free Brazing Filler Glass in Air

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5658
Author(s):  
Zhenjiang Wang ◽  
Zeng Gao ◽  
Xianli Ba ◽  
Junlong Chu ◽  
Peng He ◽  
...  
Keyword(s):  
Shear Strength ◽  
Low Temperature ◽  
Glass Powder ◽  
Leakage Rate ◽  
Lead Free ◽  
Diffusion Distance ◽  
Air Tightness ◽  
Glass Joint ◽  
Maximum Shear Strength ◽  
Short Diffusion Distance

Hypereutectic Al-Si alloys are attractive materials in the fields of electronic packaging and aerospace. A Bi2O3-ZnO-B2O3 system lead-free brazing filler glass was employed to braze hypereutectic Al-50Si alloys in air. The hypereutectic Al-50Si alloys were pre-oxidized and the low-temperature glass powder was flake-shaped in the brazing process. The effects of brazing temperature and time on joints microstructure evolution, resulting mechanical strength, and air tightness were systematically investigated. The results indicated that the maximum shear strength of the joint was 34.49 MPa and leakage rate was 1.0 × 10−10 Pa m3/s at a temperature of 495 °C for 30 min. Crystalline phases, including Bi24B2O39 and Bi2O3, were generated in the glass joint. The formation of a diffusion transition layer with a thickness of 3 μm, including elements of Al, Si, Zn, Bi, Na, and B, was the key to form an effective joint. The elements of Al, Si, and Bi had a short diffusion distance while the elements of Zn, Na, and B diffused in a long way under brazing condition.

scholarly journals Low Temperature Sealing Process and Properties of Kovar Alloy to DM305 Electronic Glass

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 941 ◽  
Author(s):  
Zhenjiang Wang ◽  
Zeng Gao ◽  
Junlong Chu ◽  
Dechao Qiu ◽  
Jitai Niu
Keyword(s):  
Low Temperature ◽  
Leakage Rate ◽  
Atmospheric Environment ◽  
Joint Interface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Air Tightness ◽  
Process Element ◽  
Kovar Alloy ◽  
Free Glass

The low temperature sealing of Kovar alloy to DM305 electronic glass was realized by using lead-free glass solder of the Bi2O3-ZnO-B2O3 system in atmospheric environment. The sealing process was optimized by pre-oxidation of Kovar alloy and low temperature founding of flake glass solder. The effects of sealing temperature and holding time on the properties of sealing joint were studied by means of X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), etc. The results showed that the pre-oxidized Kovar alloy and DM305 electronic glass were successfully sealed with flake glass solder at the sealing temperature of 500 °C for 20 min. Meanwhile, the joint interface had no pores, cracks, and other defects, the shear strength was 12.24 MPa, and the leakage rate of air tightness was 8 × 10−9 Pa·m3/s. During the sealing process, element Bi in glass solder diffused into the oxide layer of Kovar alloy and DM305 electronic glass about 1 μm, respectively.

Effects of In/Ce to Sn-3.5Ag Lead-Free Solder on Microstructures and Properties

2013 ◽  
Vol 749 ◽  
pp. 198-204 ◽  
Author(s):  
En Jia Chen ◽  
Xiu Chen Zhao ◽  
Ying Liu ◽  
Dong Mei Li ◽  
Jing Wei Cheng ◽  
...  
Keyword(s):  
Shear Strength ◽  
Melting Point ◽  
Solder Joint ◽  
Lead Free ◽  
Cu Substrate ◽  
Substrate Interface ◽  
Smelting Method ◽  
Joint Element ◽  
Free Solder ◽  
Maximum Shear Strength

The Sn-3.5Ag based lead-free electronic solder doped with element In /Ce were prepared respectively using a smelting method with protection by molten salt (SMPMS). The effects of In addition and Ce addition on microstructure, melting point and wettability of Sn-3.5Ag solder were investigated comparatively. And the effects of addition on the intermetallic compound (IMC) layer formed at solder/Cu substrate interface and the shear strength of solder joint were also studied. The results showed that appropriate In or Ce addition can refine Ag3Sn grains and improve the shear strength of solder joint. Element In can significantly reduce the melting point, narrow the melting range of the solder alloy and improve wettability on Cu substrate. When the content of In was 3%, the spreading area was the largest and the wettability was the best. The addition of Ce can efficiently reduce the thickness of the IMC layer grown at the solder/Cu substrate interface and improve the shear strength of solder joint. When the content of Ce was 0.5%, the solder joint had the minimum average IMC thickness and the maximum shear strength.

Shear Strength and Dsc Analysis of High-Temperature Solders

2013 ◽  
Vol 58 (2) ◽  
pp. 529-533 ◽  
Author(s):  
R. Koleňák ◽  
M. Martinkovič ◽  
M. Koleňáková
Keyword(s):  
Shear Strength ◽  
High Temperature ◽  
Lead Free ◽  
Dsc Analysis ◽  
Ultrasonic Activation ◽  
Metallic Substrates ◽  
Cu Substrate ◽  
Lead Free Solders

The work is devoted to the study of shear strength of soldered joints fabricated by use of high-temperature solders of types Bi-11Ag, Au-20Sn, Sn-5Sb, Zn-4Al, Pb-5Sn, and Pb-10Sn. The shear strength was determined on metallic substrates made of Cu, Ni, and Ag. The strength of joints fabricated by use of flux and that of joints fabricated by use of ultrasonic activation without flux was compared. The obtained results have shown that in case of soldering by use of ultrasound (UT), higher shear strength of soldered joints was achieved with most solders. The highest shear strength by use of UT was achieved with an Au-20Sn joint fabricated on copper, namely up to 195 MPa. The lowest average values were achieved with Pb-based solders (Pb-5Sn and Pb-10Sn). The shear strength values of these solders used on Cu substrate varied from 24 to 27 MPa. DSC analysis was performed to determine the melting interval of lead-free solders.

KAISER ALUMINUM ALLOY KA62

Alloy Digest ◽  
1999 ◽  
Vol 48 (10) ◽  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Aluminum Alloy ◽  
Physical Properties ◽  
Surface Treatment ◽  
Physical And Mechanical Properties ◽  
Heat Treating ◽  
Lead Free ◽  
Kaiser Aluminum

Abstract Kaiser Aluminum alloy KA62 (Tennalum alloy KA62) is a lead-free alternative to 6262. It offers good machinability and corrosion resistance and displays good acceptance of coatings (anodize response). It can be used in place of 6262 because its physical and mechanical properties are equivalent to those of 6262 (see Alloy Digest Al-361, September 1999). This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, and surface treatment. Filing Code: AL-362. Producer or source: Tennalum, A Division of Kaiser Aluminum.

AMPCOLOY 495

Alloy Digest ◽  
1966 ◽  
Vol 15 (11) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Low Temperature ◽  
Physical Properties ◽  
High Strength ◽  
Heat Treating ◽  
Aluminum Bronze ◽  
High Manganese ◽  
Temperature Performance

Abstract AMPCOLOY 495 is a high manganese type of aluminum bronze recommended where high strength and corrosion resistance are required along with good weldability. It is recommended for marine equipment and ship propellers. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fracture toughness, creep, and fatigue. It also includes information on low temperature performance and corrosion resistance as well as casting, forming, heat treating, machining, and joining. Filing Code: Cu-171. Producer or source: Ampco Metal Inc..

AWHF STEEL

Alloy Digest ◽  
1972 ◽  
Vol 21 (6) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Low Temperature ◽  
Physical Properties ◽  
Heat Treating ◽  
Steel Company ◽  
Cold Forming ◽  
Temperature Performance ◽  
Minimum Yield

Abstract AWHF STEEL is a high-formability steel produced regularly at minimum yield strengths of 45,000 and 50,000 psi and for special applications at 55,000 and 60,000 psi. It is recommended for difficult cold-forming applications that involve bending or drawing and it has good weldability. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and compressive and shear strength as well as fracture toughness and fatigue. It also includes information on low temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SA-275. Producer or source: Alan Wood Steel Company.

Online-Joining of C/SiC-C/SiC via Slurry Reaction and Precursor Infiltration and Pyrolysis Process with C/SiC Pins

2012 ◽  
Vol 531-532 ◽  
pp. 135-140 ◽  
Author(s):  
Yu Di Zhang ◽  
Hai Feng Hu ◽  
Chang Rui Zhang ◽  
Guang De Li
Keyword(s):  
Shear Strength ◽  
Carbon Fiber ◽  
Flexural Strength ◽  
Fracture Mode ◽  
Pyrolysis Process ◽  
Strong Bond ◽  
Sic Composites ◽  
Maximum Shear Strength ◽  
Application Prospects ◽  
Complex Components

C/SiC composites have widely application prospects in the field of aeronautic and aerospace for their excellent properties. The joining of C/SiC composites is a key to fabricate large and complex components. In this paper, 1D C/SiC pins were prepared by precursor infiltration and pyrolysis (PIP) process and used to join C/SiC composites by Slurry react (SR) and PIP process. The shear strength of the C/SiC pins with different carbon fiber volumes was investigated with the maximum shear strength as high as 339.46MPa. Influences of C/SiC pins on the joining properties of C/SiC composites were studied. The shear strength and flexural strength of C/SiC-C/SiC joining are improved from 9.17MPa and 30.41MPa without pins to 20.06MPa and 75.03MPa with one C/SiC pin (diameter 2mm), respectively. The reliability of C/SiC-C/SiC joining is also improved with C/SiC pins in that the fracture mode changes from catastrophic without pins to non-catastrophic. The SEM photos show a strong bond between joining layer and C/SiC composites without obvious interface.

A flexible lead-free piezoelectric nanogenerator based on vertically aligned BaTiO3 nanotube arrays on a Ti-mesh substrate

RSC Advances ◽  
2016 ◽  
Vol 6 (84) ◽  
pp. 81426-81435 ◽  
Author(s):  
Ermias Libnedengel Tsege ◽  
Gyu Han Kim ◽  
Venkateswarlu Annapureddy ◽  
Beomkeun Kim ◽  
Hyung-Kook Kim ◽  
...  
Keyword(s):  
Low Temperature ◽  
Titanium Oxide ◽  
Hydrothermal Process ◽  
Lead Free ◽  
Nanotube Arrays ◽  
Titanium Oxide Nanotubes ◽  
Vertically Aligned ◽  
Ti Mesh

A novel, flexible lead-free piezoelectric nanogenerator was developed using a uniform BaTiO3 film; synthesized by in situ conversion of titanium oxide nanotubes in a low temperature hydrothermal process.

scholarly journals Determination of reinforcing bars for tests of hollow core slabs with continuity

2013 ◽  
Vol 6 (6) ◽  
pp. 903-932
Author(s):  
A. P. Santos ◽  
M. A. Ferreira ◽  
R. C. Carvalho ◽  
L. M. Pinheiro
Keyword(s):  
Shear Strength ◽  
The Other ◽  
Hollow Core ◽  
Reinforcing Bars ◽  
Simply Supported ◽  
Resistance Moment ◽  
Hollow Core Slab ◽  
Maximum Shear Strength

The structural designs of floors formed by hollow core slabs usually consider these as simply-supported slabs. In recent years there have been project changes and hollow core slabs with continuity are widely used. The objective of this study is to suggest a way to calculate the reinforcement bars to be used in tests with continuity provided by a structural topping. Thus, this paper presents a method based on the maximum positive resistance moment and maximum shear strength of a hollow core slab. The method is applied to a test in hollow core slab specimens which have the following dimensions: 2 m width, 6 m long, and 21 cm high. The results indicated that the method was satisfactory to the performed test, and can therefore be applied to the other test configurations or even designs.

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