Plastic Deformation of Some Polymers in Solid State Extrusion

1971 ◽  
Vol 20 (212) ◽  
pp. 606-609 ◽  
Author(s):  
Kiyohisa IMADA ◽  
Tuneo YAMAMOTO ◽  
Kenji KANEKIYO ◽  
Motowo TAKAYANAGI
Keyword(s):  
Plastic Deformation ◽  
Solid State

Solid-state plastic deformation in the dynamic interior of a differentiated asteroid

2013 ◽  
Vol 6 (2) ◽  
pp. 93-97 ◽  
Author(s):  
B. J. Tkalcec ◽  
G. J. Golabek ◽  
F. E. Brenker
Keyword(s):  
Plastic Deformation ◽  
Solid State

Solid state reactions in the CuZn system induced by plastic deformation at room temperature

1988 ◽  
Vol 145 ◽  
pp. 261-270 ◽  
Author(s):  
S. Martelli ◽  
G. Mazzone ◽  
S. Scaglione ◽  
M. Vittori
Keyword(s):  
Plastic Deformation ◽  
Solid State ◽  
Room Temperature ◽  
Solid State Reactions

Characterization o Solid-State Vortices Associated with the Friction-Stir Welding of Copper to Aluminum

1998 ◽  
Vol 4 (S2) ◽  
pp. 530-531
Author(s):  
R. D. Flores ◽  
L. E. Murr ◽  
E. A. Trillo
Keyword(s):  
Plastic Deformation ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Solid State ◽  
Weld Zone ◽  
Thick Plates ◽  
6061 Aluminum Alloy ◽  
Friction Stir ◽  
The Past ◽  
Joining Process

Although friction-stir welding has been developing as a viable industrial joining process over the past decade, only little attention has been given to the elucidation of associated microstructures. We have recently produced welds of copper to 6061 aluminum alloy using the technique illustrated in Fig. 1. In this process, a steel tool rod (0.6 cm diameter) or head-pin (HP) traverses the seam of 0.64 cm thick plates of copper butted against 6061-T6 aluminum at a rate (T in Fig. 1) of 1 mm/s; and rotating at a speed (R in Fig. 1) of 650 rpm (Fig. 1). A rather remarkable welding of these two materials results at temperatures measured to be around 400°C for 6061-T6 aluminum welded to itself. Consequently, the metals are stirred into one another by extreme plastic deformation which universally seems to involve dynamic recrystallization in the actual weld zone. There is no melting.

EXPERIMENTAL INVESTIGATION OF CHALCOCITE: ANNEALING AND PLASTIC DEFORMATION AT ELEVATED TEMPERATURES

1965 ◽  
Vol 2 (2) ◽  
pp. 98-117
Author(s):  
Raymond Davies
Keyword(s):  
Experimental Investigation ◽  
Plastic Deformation ◽  
Solid State ◽  
Grain Growth ◽  
Annealing Time ◽  
Silica Glass ◽  
Elevated Temperatures ◽  
Recrystallization Behavior ◽  
Vapor Pressures ◽  
Sulfur Vapor

The recrystallization behavior and deformation of synthetic chalcocite (Cu2S) in the temperature range 400–725 °C was studied microscopically after the compound was annealed in evacuated silica glass capsules and heated under differential pressures in sealed gold capsules. The temperature of recrystallization and grain growth ascribed to the hexagonal cubic inversion, at sulfur vapor pressures much less than 1 atmosphere, was determined at 465 ± 5 °C, with annealing time of [Formula: see text].Experiments involving differential pressures of 8 000 p.s.i. show that chalcocite in the solid state becomes considerably more mobile above 563 ± 10 °C and can readily be injected as a plastic mass to form veins without preservation of deformational textures.Natural bornite and natural galena may also be injected under differential pressure at 640 °C, but some unhealed fractures remain. Flow structure is well-preserved in galena and, under certain conditions, in bornite.Mixtures of bornite and pyrite flowed and recrystallized to chalcopyrite and bornite with exsolved chalcopyrite. No evidence of flowage remained.Chalcopyrite and pyrrhotite are resistant to injection under similar differential pressures and temperatures.

scholarly journals Using the Hybrid Metal Extrusion & Bonding (HYB) Process for Butt Welding of 4 mm Plates of AA6082-T6

2018 ◽  
Vol 188 ◽  
pp. 03017
Author(s):  
Lise Sandnes ◽  
Øystein Grong ◽  
Jan Torgersen ◽  
Filippo Berto
Keyword(s):  
Plastic Deformation ◽  
Solid State ◽  
Yield Strength ◽  
Heat Affected Zone ◽  
Aluminium Alloys ◽  
Base Material ◽  
Butt Welding ◽  
Exploratory Investigation ◽  
Metal Extrusion ◽  
Solid State Joining

Hybrid Metal Extrusion & Bonding is a new solid state joining technique developed for aluminium alloys. By the use of filler material addition and plastic deformation sound joints can be produced at operational temperatures below 400 °C. This makes the HYB process more flexible and less vulnerable to defects compared to conventional solid state processes. Here, we present the results form an exploratory investigation of the mechanical integrity of a 4 mm AA6082-T6 HYB joint, covering both hardness, tensile and Charpy V-notch testing of different weld zones. The joint is found to be free from internal defects like pores, cavities and kissing bonds. Still, a soft heat affected zone (HAZ) is present. The joint yield strength is 54 % of the base material, while the corresponding joint efficiency is 66%. Therefore, there is a potential for further optimization of the HYB process. This work is now in progress.

Mathematical Modeling of Solid-State Diffusion during Mechanical Alloying

2006 ◽  
Vol 249 ◽  
pp. 105-110 ◽  
Author(s):  
Boris B. Khina ◽  
Boleslaw Formanek
Keyword(s):  
Plastic Deformation ◽  
Solid State ◽  
Mechanical Alloying ◽  
Solid Solutions ◽  
Point Defects ◽  
Physical Mechanism ◽  
Solid State Diffusion ◽  
State Diffusion ◽  
Wide Range ◽  
Supersaturated Solid Solutions

It is known experimentally that solid-state interdiffusion is substantially enhanced during plastic deformation. This is especially noticeable in Mechanical Alloying (MA) which is used for producing a wide range of metastable materials (supersaturated solid solutions, amorphous phases, nanostructures) with unique properties. However, a physical mechanism of enhanced diffusion during MA is not clearly understood yet, and a comprehensive model of this complex phenomenon has not been developed so far. Moreover, the role of the diffusion process in MA is hotly debated in literature. In this work a new, self-consistent mathematical model of solid-state interdiffusion in a binary substitutional system A-B during periodic plastic deformation is developed. The model includes basic physical factors that affect diffusion, such as generation of non-equilibrium point defects by gliding screw dislocations during deformation and their relaxation in periods between impacts. The cross-link terms are considered, and interaction of point defects with edge dislocations and incoherent phase boundary A/B is taken into account. Computer simulation is performed using realistic data (e.g., quasi-equilibrium self-diffusion coefficients known in literature) and the process parameters typical of MA in a vibratory mill. A repeated “deformation-rest” cycle is considered. The results of modeling reveal the physical mechanism of the enhancement of solid-state diffusion by periodic plastic deformation during MA and demonstrate that within the frame of this approach supersaturated solid solutions can form within a reasonably short processing time.

Mechanoluminescence of Coloured Alkali Halide Crystals

2015 ◽  
Vol 361 ◽  
pp. 121-176 ◽  
Author(s):  
B.P. Chandra ◽  
V.K. Chandra ◽  
Piyush Jha
Keyword(s):  
Plastic Deformation ◽  
Solid State ◽  
Impact Velocity ◽  
Alkali Halide ◽  
Applied Pressure ◽  
Gas Discharge ◽  
Mechanical Interaction ◽  
Dislocation Band ◽  
Alkali Halide Crystals ◽  
The Impact

The present paper reports both the experimental and mathematical aspects of elastico-mechanoluminescence (EML), plastico-mechanoluminescence (PML) and fracto-mechanoluminescence (FML) of coloured alkali halide crystals in detail, and thereby provides a deep understanding of the related phenomena. The additively coloured alkali halide crystals do not show ML during their elastic and plastic deformation. The ML emission during the elastic deformation takes place due to the mechanical interaction between bending dislocation segments and F-centres, and the ML emission during plastic deformation takes place due to the mechanical interaction between the moving dislocations and F-centres. The ML emission during fracture is also caused by the mechanical interaction between the moving dislocations and F-centres; however, in certain hard crystals like LiF, NaCl, NaF, etc., fracto ML also occurs due to the gas discharge caused by the creation of oppositely charged walls of cracks. The EML, PML, and solid state FML spectra of coloured alkali halide crystals are similar to their thermoluminescence spectra and afterglow spectra. However, the fracto ML spectra of certain hard crystals like LiF, NaCl, NaF, etc., also contain gas discharge spectra. The solid state ML spectra of coloured alkali halide crystals can be assigned to deformation-induced excitation of halide ions inV2-centres or in other hole-centres. Whereas, the intensity of EML and FML increases linearly with the applied pressure and the impact velocity, the intensity of PML increases quardratically with the applied pressure and the impact velocity because of the plastic flow of the crystals. Both Imand ITincrease with the density of F-centres in the crystals and strain rate of the crystals; however, they are optimum for a particular temperature of the crystals. The ML of diminished intensity also appears during the release of applied pressure. Expressions are derived for the elastico ML, plastico ML and fracto ML of coloured alkali halide crystals, in which a good agreement is found between the experimental and theoretical results. Many parameters of crystals such as band gap between the dislocation band and interacting F-centre energy level, radius of interaction between dislocations and F-centres, pinning time of dislocations, work hardening exponent, velocity of cracks, rise time of applied pressure, lifetime of electrons in the dislocation band, lifetime of electrons in shallow traps, diffusion time of holes, critical velocity of impact, etc., can be determined from the ML measurements. The ML of coloured alkali halide crystals has potential for self-indicating method of monitoring the microscopic and macroscopic processes; mechanoluminescence dosimetry; understanding dislocation bands in crystals; interaction between the dislocations and F-centres; dynamics of dislocations; deformation bleaching of coloration, etc. The ML of coloured alkali halide crystals has also the potential for photography, ML memory, and it gives information about slip planes, compression of crystals, fragmentation of crystals, etc.Contents of Paper

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