Pick-up defect mechanism in hot extrusion of Al-Mg-Si series alloy

Vacancies are introduced into the crystal phase during quenching of rapid solidified materials. Cavity formation occurs because of the coalescence of the vacancies into a cluster. However, because of the high mobility of vacancies at high temperature, most of them will diffuse back into the liquid phase, and some will be lost to defects such as dislocations. Oxygen is known to stabilize cavities by decreasing the surface energy through a chemisorption process. These stabilized cavities, furthermore, act as effective nucleation sites for precipitates to form during aging. Four different types of powders with different oxygen contents were prepared by gas atomization processing. The atomized powders were then consolidated by hot extrusion at 900 °C with an extrusion ratio 10,5:1. After consolidation, specimens were heat treated at 1000 °C for 1 hr followed by water quenching. Finally, the specimens were aged at 600 °C for about 800 hrs. TEM samples were prepared from the gripends of tensile specimens of both unaged and aged alloys.

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ALCOA ULTRALLOY X6020

Alloy Digest ◽

10.31399/asm.ad.al0340 ◽

1996 ◽

Vol 45 (12) ◽

Keyword(s):

Corrosion Resistance ◽

Surface Treatment ◽

Tensile Properties ◽

Lead Free ◽

Aluminum Association ◽

Wire Rod ◽

Series Alloy ◽

6Xxx Series

Abstract UltrAlloy is a lead-free, enhanced machining product with the inherent benefits of a 6xxx-series alloy. The alloy is produced as a cold-finished rod and bar with strength levels comparable to 6262. The alloy is registered with the Aluminum Association as X6020. This datasheet provides information on composition, microstructure, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, machining, joining, and surface treatment. Filing Code: AL-340. Producer or source: ALCOA Wire, Rod & Bar Division. Originally published September 1996, corrected December 1996.

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MUSTANG-LC

Alloy Digest ◽

10.31399/asm.ad.ts0192 ◽

1967 ◽

Vol 16 (4) ◽

Keyword(s):

Physical Properties ◽

High Speed ◽

High Speed Steel ◽

Hot Extrusion ◽

Heat Treating ◽

Hot Forming ◽

Steel Company ◽

Extrusion Dies ◽

Die Life

Abstract Mustang-LC is a tungsten-molybdenum high-speed steel specially developed for hot work applications requiring long die life. It is recommended for hot forming and swaging dies, hot extrusion dies, hot punches, etc. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on forming, heat treating, machining, and joining. Filing Code: TS-192. Producer or source: Jessop Steel Company.

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UNS T20819

Alloy Digest ◽

10.31399/asm.ad.ts0496 ◽

1989 ◽

Vol 38 (2) ◽

Keyword(s):

Elevated Temperatures ◽

Hot Extrusion ◽

Heat Treating ◽

High Toughness ◽

Extrusion Dies ◽

Extrusion Die ◽

Steel Mills ◽

Temperature Performance ◽

Heat Checking ◽

Resistance To Heat

Abstract UNS T20819 is a hot-work tool and die steel that is characterized by excellent resistance to shock and abrasion at elevated temperatures. This steel provides relatively high toughness and outstanding resistance to heat checking and softening at elevated temperatures. Among its many applications are hot-punch tools, forging dies and inserts, brass extrusion dies, permanent molds for brass casting and hot-extrusion die inserts for steel. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-496. Producer or source: Tool steel mills.

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BiCMOS Die Sort Yield Improvement from Isolation of a Localized Defect Mechanism and Precision TEM Cross Section

ISTFA 1997: Conference Proceedings from the 23rd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa1997p0321 ◽

1997 ◽

Author(s):

J. Douglass ◽

T. D. Myers ◽

F. Tsai ◽

R. Ketcheson ◽

J. Errett

Keyword(s):

Electron Microscopy ◽

Cross Section ◽

Focused Ion Beam ◽

Yield Loss ◽

Process Analysis ◽

Ion Beam ◽

Yield Improvement ◽

Transmission Electron ◽

Defect Mechanism ◽

Water Residue

Abstract This paper describes how the authors used a combination of focused ion beam (FIB) microprobing, transmission electron microscopy (TEM), and data and process analysis to determine that localized water residue was causing a 6% yield loss at die sort.

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The Application of FIB Voltage-Contrast Technique Combining with TEM on Subtle Defect Analysis: Via Delamination After TC

ISTFA 1997: Conference Proceedings from the 23rd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa1997p0115 ◽

1997 ◽

Author(s):

X. Yang ◽

X. Song

Keyword(s):

Cross Section ◽

Focused Ion Beam ◽

Ion Beam ◽

New Product ◽

Defect Analysis ◽

Transmission Electron ◽

Contrast Technique ◽

Defect Mechanism ◽

Open Defect ◽

Voltage Contrast

Abstract Novel Focused Ion Beam (FIB) voltage-contrast technique combined with TEM has been used in this study to identify a certain subtle defect mechanism that caused reliability stress failures of a new product. The suspected defect was first isolated to a unique via along the row through electrical testing and layout analysis. Static voltage contrast of FIB cross-section was used to confirm the suspected open defect at the via. Precision Transmission Electron Microscope (TEM) was then used to reveal the detail of the defect. Based on the result, proper process changes were implemented. The failure mode was successfully eliminated and the reliability of the product was greatly improved.

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