Improvement of Fracture Toughness in 7475 Aluminum Alloy by the RRA (Retrogression and Re-Aging) Process

In this paper, the effect of two-step aging treatment on microstructure and fracture toughness of 7085 aluminum alloy were investigated by using tear tests to carry out the fracture toughness tests of the alloy and using optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to analyze the microstructure. The results showed the main precipitates in the alloy were GP zones and η' phases in the grains after 118°C/6h aging treatment. With further secondary aging treatment, grain boundaries precipitates (GBPs) grew up, and the precipitate-free zone (PFZ) showed up, the increasing proportion of intergranular failure was occurred and the fracture toughness decreased. With further prolonging of the secondary aging treatment time, precipitates in the grains tended to be coarser, the GBPs became discontinuous ,PFZ became wider, and there were decreasing proportion of the intergranular failure and increasing proportion of the transgranular failure showing on the fracture morphologies, the fracture toughness of 7085 aluminum alloy increased.

Download Full-text

Effect of Secondary Aging Process on the Structure and Properties of 7050 Aluminum Alloy Forging

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.861.57 ◽

2020 ◽

Vol 861 ◽

pp. 57-64

Author(s):

Wei Wei He ◽

Min Hao ◽

Hui Qu Li ◽

Liang Wang ◽

Jun Zhou Chen

Keyword(s):

Fracture Toughness ◽

Aluminum Alloy ◽

Electron Microscope ◽

Aging Time ◽

Aging Process ◽

Fracture Mechanisms ◽

Second Stage ◽

7050 Aluminum Alloy ◽

Stress Corrosion Resistance ◽

Precipitation Phase

The effect of the second-stage aging process on the tensile properties, fracture toughness and electrical conductivity of 7050 aluminum alloy die forgings was studied, and the mechanism of strengthening and toughening was analyzed by transmission electron microscope and scanning electron microscope. The results show that with the extension of the second-stage aging time, the morphology of the precipitation phase remains unchanged, but the average radius of the precipitation phase and the distance between each other gradually increase. The fracture modes at this aging temperature are mixed fracture mechanisms of dimple fracture and intergranular fracture, and the number of dimple fractures increases with time. With the extension of the second-stage aging time, the strength of the alloy decreases, and the fracture toughness and stress corrosion resistance increase. The alloys heat-treated at 120°C×6 h +177°C×6~8 h two-stage aging process have excellent comprehensive properties.

Download Full-text

DURALCAN F3S.xxS

Alloy Digest ◽

10.31399/asm.ad.al0329 ◽

1994 ◽

Vol 43 (10) ◽

Keyword(s):

Fracture Toughness ◽

Silicon Carbide ◽

Compressive Strength ◽

Aluminum Alloy ◽

High Temperature ◽

Base Alloy ◽

Alloy Matrix ◽

Reinforced Composite ◽

Temperature Performance ◽

Aluminum Alloy Matrix

Abstract Duralcan F3S.xxS is a heat treatable aluminum alloy-matrix gravity composite. The base alloy is similar to Aluminum 359 (Alloy Digest Al-188, July 1969); the discontinuously reinforced composite is silicon carbide. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength as well as fracture toughness and fatigue. It also includes information on high temperature performance. Filing Code: AL-329. Producer or source: Alcan Aluminum Corporation.

Download Full-text

IMPALCO 770

Alloy Digest ◽

10.31399/asm.ad.al0120 ◽

1962 ◽

Vol 11 (11) ◽

Keyword(s):

Fracture Toughness ◽

Corrosion Resistance ◽

Shear Strength ◽

Aluminum Alloy ◽

Physical Properties ◽

Tensile Properties ◽

High Strength ◽

Heat Treating ◽

High Strength Aluminum Alloy ◽

Structural Parts

Abstract IMPALCO 770 is a heat treatable, high strength aluminum alloy available in bar form for machining applications. It is recommended for highly stressed structural parts. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fracture toughness and fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-120. Producer or source: Imperial Aluminium Company Ltd.

Download Full-text

FEDERATED F150.5

Alloy Digest ◽

10.31399/asm.ad.al0219 ◽

1975 ◽

Vol 24 (11) ◽

Keyword(s):

Fracture Toughness ◽

Aluminum Alloy ◽

High Temperature ◽

Physical Properties ◽

Tensile Properties ◽

High Strength ◽

Heat Treating ◽

Alloying Elements ◽

Light Weight ◽

Temperature Performance

Abstract FEDERATED F150.5 is a heat-treatable aluminum alloy containing silicon and copper as the major alloying elements. It is recommended for high-strength, light-weight, pressure-tight castings. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as casting, heat treating, machining, and joining. Filing Code: Al-219. Producer or source: Federated Metals Corporation, ASARCO Inc..

Download Full-text

KAISER ALUMINUM ALLOY 7050

Alloy Digest ◽

10.31399/asm.ad.al0366 ◽

2000 ◽

Vol 49 (1) ◽

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Tensile Strength ◽

Aluminum Alloy ◽

Heat Treating ◽

High Fracture Toughness ◽

High Fracture ◽

Kaiser Aluminum ◽

Structural Parts ◽

Very High

Abstract Kaiser Aluminum Alloy 7050 has very high mechanical properties including tensile strength, high fracture toughness, and a high resistance to exfoliation and stress-corrosion cracking. The alloy is typically used in aircraft structural parts. This datasheet provides information on composition, physical properties, hardness, tensile properties, and shear strength as well as fracture toughness and fatigue. It also includes information on forming, heat treating, machining, and joining. Filing Code: AL-366. Producer or source: Tennalum, A Division of Kaiser Aluminum.

Download Full-text

Enhanced strength and electrical conductivities of an Al-Zn-Mg aluminum alloy through a new aging process

Materials Letters ◽

10.1016/j.matlet.2021.130586 ◽

2021 ◽

pp. 130586

Author(s):

Bin Ke ◽

Lingying Ye ◽

Yong Zhang ◽

Xiaodong Liu ◽

Yu Dong ◽

...

Keyword(s):

Aluminum Alloy ◽

Aging Process ◽

Electrical Conductivities

Download Full-text

Determination of Fracture Toughness and K-R Curve for 2524-T3 Aluminum Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.291-294.1039 ◽

2011 ◽

Vol 291-294 ◽

pp. 1039-1042

Author(s):

Wei Xie ◽

Shao Wei Tu ◽

Qi Qing Huang ◽

Ya Zhi Li

Keyword(s):

Fracture Toughness ◽

Aluminum Alloy ◽

Stress Fracture ◽

Test Data ◽

Plane Stress ◽

Crack Extension ◽

Room Temperature ◽

Mode I ◽

Average Value

In the present work, the resistance to crack extension of 2524-T3 aluminum alloy under Mode I loading was studied by using the middle-cracked tension M (T) specimens. The curve, plane-stress fracture toughness and apparent plane-stress fracture toughness were calculated by test data. The average value of measured fracture toughness at room temperature was 161 MPam1/2. The results and conclusions can be referred in airplane skin design.

Download Full-text