Diffusion Bonding of Superplastic 7075 Aluminum Alloy

1990 ◽  
Vol 196 ◽  
Author(s):  
Huang Yan ◽  
Cui Jianzhong ◽  
Ma Longxiang
Keyword(s):  
Aluminum Alloy ◽  
Base Metal ◽  
Diffusion Bonding ◽  
Joint Strength ◽  
Bonding Process ◽  
Special Method ◽  
Bonding Mechanism ◽  
7075 Aluminum Alloy ◽  
Joint Microstructure ◽  
Bond Interface

ABSTRACTBecause of the presence of surface oxide films, aluminum alloys are very difficult to join by diffusion bonding processes when there are no interlayers between mating surfaces. In the present investigation, the diffusion bonding of superplastic 7075 aluminum alloy has been carried out using a special method for surface treatment in the temperature range 500∼520°C, at pressures of 2.07∼3.OMPa, times of 90∼150min and a vaccum of 1×10−5torr. The joint strength obtained is the same as the base metal strength of the alloy, and the joint microstructure is indistinguishable from that of the base metal. In this paper, the effect of the superplastic treatment of the alloy on the bonding process is discussed, and it is proposed that the bonding mechanism is the migration of the initial bond interface caused both by the diffusion of atoms and by the growth of grains during the diffusion bonding process.

Diffusion Bonding between AZ31 Magnesium Alloy and 7075 Aluminum Alloy

2014 ◽  
Vol 618 ◽  
pp. 150-153 ◽  
Author(s):  
Zhi Tong Chen ◽  
Fei Lin ◽  
Jie Li ◽  
Fei Wang ◽  
Qing Sen Meng
Keyword(s):  
Shear Strength ◽  
Aluminum Alloy ◽  
Magnesium Alloy ◽  
Diffusion Bonding ◽  
Holding Time ◽  
Az31 Magnesium Alloy ◽  
Diffusion Welding ◽  
7075 Aluminum Alloy ◽  
Micro Hardness ◽  
Welding Temperature

A study on vacuum diffusion bonding between as-extruded AZ31 magnesium alloy and 7075 aluminum alloy was carried out according to atomic diffusion theory. Recrystallization annealing was used for grain refinement of AZ31 magnesium alloy and 7075 aluminum alloy before the diffusion welding. The quality of the bonding joints was checked by shear test, micro-hardness test and microstructure analysis. Experimental results showed that the welding temperature and holding time have a great effect on the joint shear strength. The maximum of shear strength was 38.41MPa under the temperature of 470°C and the holding time of 60min. The result of micro-hardness measurement showed that the micro-hardness of welded joints was maximum. Three kinds of intermetallic compounds, Mg2A13, MgAl and Mgl7Al12, formed at the interfacial transition zone at 470°C.

Diffusion Bonding of Mg-AZ31B/Al-6061 and Characteristics with Pressure and with no Pressure

2013 ◽  
Vol 834-836 ◽  
pp. 812-815
Author(s):  
Ming Zhao ◽  
Dong Ying Ju
Keyword(s):  
Solid Solution ◽  
Diffusion Bonding ◽  
Bonding Process ◽  
Bonding Mechanism ◽  
Al 6061 ◽  
Process Characteristics ◽  
Interface Characteristics ◽  
Aluminum Solid Solution ◽  
Crystal Model ◽  
Bonding Method

The study is diffusion bonding of Mg-AZ31 and Al-6061 under pressure and no pressure by using the direct bonding method. After bonding process, characteristics phase in interface and bonding boundaries of Mg-AZ31/Al-6061 were characterized . The diffusion formation was observed by SEM. Aluminum solid solution and Mg17Al12 alloy phase was proved by analysis of XRD. In the process of measurement, crystalline structure of nearby interface characteristics phase was analyzed in detail by TEM. Based on the above analysis, the crystal model of the magnesium alloy and aluminum alloys was established under pressure, and the bonding mechanism was discussed. The results show that the bonding materials could be bonded under no pressure and the structure of bonding interface is more optimized than pressure.

scholarly journals Effect of Post-Weld Heat Treatment on the Solid-State Diffusion Bonding of 6061 Aluminum Alloy

2021 ◽  
Vol 11 (20) ◽  
pp. 9660
Author(s):  
Chun-Hao Chen ◽  
Yu-Kai Sun ◽  
Yu-Chang Lai ◽  
Shih-Ying Chang ◽  
Tung-Han Chuang
Keyword(s):  
Heat Treatment ◽  
Shear Strength ◽  
Aluminum Alloy ◽  
Solid State ◽  
Diffusion Bonding ◽  
Joint Strength ◽  
Post Weld Heat Treatment ◽  
Solid State Diffusion ◽  
State Diffusion ◽  
Weld Heat

The precipitation-hardenable aluminum alloy 6061 (AA 6061) is favored for aerospace components and automotive parts. However, the tenacious oxide layer on the surface greatly limits the quality and applicability of joining AA 6061. In this study, the joining method of solid-state diffusion bonding was implemented for AA 6061 plates, and the effects of post-weld heat treatment (PWHT) on the joint interface were investigated. The bonding temperatures were within the range of 500–530 °C, and the time periods varied from 30 to 240 min under a static pressure of 5 MPa in a vacuum. The diffusion bonded specimens were subjected to T4- and T6-PWHT to improve the bonding quality. The interfacial microstructure of the joints was analyzed by scanning electron microscopy, and the mechanical properties were evaluated with shear tests. The experimental results showed that the shear strength of the diffusion bonded joint could reach around 71.2 MPa, which was highly dependent on bonding temperature and holding time, and T6-PWHT further enhanced it to over 100 MPa. The effects of PWHT on the diffusion bonded AA 6061 joint were investigated, and the fractography on the sheared surfaces indicated that PWHT-T6 played an important role in enhancing joint strength, which was consistent with the measured shear strength. The sequential PWHT for AA 6061 after diffusion bonding was proven to be feasible for bonding of AA 6061 parts, and the joint strength was sufficient for industrial needs.

Mechanical and Microstructural Characterization of Diffusion Bonded 800H

2020 ◽  
Author(s):  
Heramb P. Mahajan ◽  
Mohamed Elbakhshwan ◽  
Bruce C. Beihoff ◽  
Tasnim Hassan
Keyword(s):  
Mechanical Property ◽  
Base Metal ◽  
Microstructure Evolution ◽  
Diffusion Bonding ◽  
Elevated Temperatures ◽  
Bonding Process ◽  
Atomic Diffusion ◽  
Alloy 800H ◽  
Tensile Fatigue ◽  
Creep Fatigue

Abstract Compact heat exchangers have high compactness and efficiency, which is achieved by joining a stack of chemically etched channeled plates through diffusion bonding. In the diffusion bonding process, compressive stress is applied on plates at elevated temperatures for a specified period. These conditions lead to atomic diffusion, which results in the joining of all plates into a monolithic block. The diffusion bonding temperatures are above recrystallization temperatures, which changes the mechanical and microstructural properties of the bonded metal. Hence, diffusion bonded material needs mechanical and microstructural property evaluation. In this study, Alloy 800H is selected to study the influence of the diffusion bonding process on mechanical and microstructure properties of base metal. A series of tensile, fatigue, creep, and creep-fatigue experiments are conducted on base metal 800H (BM 800H) and diffusion bonded 800H (DB 800H) to explore the mechanical properties. Microstructure evolution during diffusion bonding is studied and presented in the paper. The mechanical and microstructural observations indicated ductile fracture at room temperature and brittle failure with bond delamination at elevated temperatures. The microstructure evolution during diffusion bonding is studied through tensile, fatigue, creep and creep-fatigue tests, and the implied root causes for the mechanical property changes are investigated. Efforts are made to correlate the microstructure change with mechanical property change in DB 800H.

Microstructure Control and Mechanical Properties of Multipass Friction Stir Processed High Strength Aluminum Alloy

2012 ◽  
Vol 735 ◽  
pp. 316-321 ◽  
Author(s):  
Yutaka Matsuda ◽  
Goroh Itoh ◽  
Yoshinobu Motohashi
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Base Metal ◽  
Friction Stir Processing ◽  
Superplastic Deformation ◽  
High Strength ◽  
7075 Aluminum Alloy ◽  
Friction Stir ◽  
High Strength Aluminum Alloy ◽  
Equiaxed Grains

Friction stir processing (FSP) causes fine-equiaxed microstructure[1]. In this study, microstructure and mechanical properties of a 7075 aluminum alloy subjected to multipass FSP, MP-FSP, are assessed. A new zone, PBZ, has been discovered between stir zones, SZs. The SZs are composed of fine-equiaxed grains, while PBZs are composed of two types of (fine-equiaxed and coarse-elongated) grains, both of which are still finer than those of base metal. Elongation at 773K of MP-FSPed specimen becomes larger than that of base metal, based on superplastic deformation due to the finer microstructure. Local elongation is smaller in PBZ than in SZ.

Kinetics of Grain Growth Across Bond Interface During Diffusion Bonding

1990 ◽  
Vol 196 ◽  
Author(s):  
Huang Yan ◽  
Cui Jianzhong ◽  
Ma Longxiang
Keyword(s):  
Grain Growth ◽  
Diffusion Bonding ◽  
Joint Strength ◽  
Process Variables ◽  
Pressure Time ◽  
State Diffusion ◽  
Controlling Mechanism ◽  
Bond Interface ◽  
Hot Rolled ◽  
Kinetics Of

ABSTRACTGenerally, the elimination of the voids in bond interface is considered to be the rate-controlling mechanism for diffusion bonding. In an earlier paper, the author proposed a new theoretical model for solid-state diffusion bonding of similar matals, in which the grain growth across the bond interface was considered to be the governing mechanism for diffusion bonding. The aim of the model is to understand how the joint strength is affected both by process variables (temperature, pressure, time) and by the microstructures of the materials being joined. In this paper, the mechanism of grain growth and recrystallization is discussed, and the calculation of an appropriate kinetic equation is made based on a diffusion bonding experiment on a hot-rolled 7075 aluminum alloy. The calculated results basically agree with those of the experiment.

Effect of ultrasonic melt treatment on the tribological behavior of 7075 aluminum alloy

2020 ◽  
Vol 62 (12) ◽  
pp. 1243-1250
Author(s):  
Fahri Vatansever ◽  
Alpay Tamer Erturk ◽  
Erol Feyzullahoglu
Keyword(s):  
Aluminum Alloy ◽  
Tribological Behavior ◽  
7075 Aluminum Alloy ◽  
Melt Treatment ◽  
Ultrasonic Melt Treatment
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