Effect of Pre-Treatment on the Precipitation Hardening of a Novel Al-Mg-Si Alloy

2014 ◽  
Vol 881-883 ◽  
pp. 1374-1377
Author(s):  
Li Wei Quan ◽  
Rui Wu ◽  
Da Ran Fang ◽  
Yuan Yuan Liu ◽  
Chuan Cai Wang
Keyword(s):  
Vickers Hardness ◽  
Room Temperature ◽  
Artificial Aging ◽  
Precipitation Hardening ◽  
Natural Aging ◽  
The Other ◽  
Bake Hardening ◽  
Automotive Body ◽  
Pre Treatment

Al-Mg-Si alloy is used to investigate the bake-hardening response as automotive body panels. Natural aging followed by artificial aging at 170°C was carried on to study the effect of delaying at room temperature. Two methods are carried on to investigate the effect of pre-treatment on hardening response of Al-Mg-Si alloy. One is pre-aging in the range 80-140°Cfollowed by artificial aging at 170°C after natural aging for the same periods, and the other is retrogression treatment followed by artificial aging at 170°C after natural aging for the same periods. The properties of the alloy are tested by Vickers hardness measurements. And it is found that the optimal pre-ageing is 170°C for 30min and the opimal retrogression treatment is 230°C for 15s.

Pre-Aging and Maturing Effects on the Precipitation Hardening of an Al-Mg-Si Alloy

2010 ◽  
Vol 297-301 ◽  
pp. 68-73
Author(s):  
T. Abid ◽  
A. Boubertakh ◽  
S. Hamamda
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Artificial Aging ◽  
Precipitation Hardening ◽  
Natural Aging ◽  
Undesirable Effect ◽  
Scanning Calorimetry ◽  
Experimental Conditions ◽  
Later Phase ◽  
Scanning Electron

The effect of pre-aging and maturing at room temperature on the hardening response of an Al-Mg-Si alloy is investigated using differential scanning calorimetry (DSC), hardness measurements (Hv) and scanning electron microscopy (SEM).Two experimental conditions are examined. First, natural aging for different times (3 weeks and 1 month) followed by artificial aging at 180°C as a function of time. Second, pre-aging at temperatures in the range 75-100°C followed by artificial aging at 180°C after natural aging for the same periods. The present results indicate that the effect of the pre-aging just after the heating and quenching is used in order to correct the undesirable effect of aging at room temperature. However, during the artificial aging, the alloy hardening becomes faster. Aged samples which have already undergone pre-aging and maturing reveal the precipitation of ''phase. This later phase has the highest hardness value.

Dependence of Vickers Hardness on Annealing Temperature at Co/Cu Multilayered Films

2007 ◽  
Vol 561-565 ◽  
pp. 2399-2402
Author(s):  
Yoshihisa Kaneko ◽  
H. Sakakibara ◽  
Satoshi Hashimoto
Keyword(s):  
Thermal Stability ◽  
Vickers Hardness ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Copper Substrate ◽  
The Other ◽  
Multilayered Structures ◽  
Multilayered Films ◽  
Hardness Tests ◽  
Thermal Stability Of

Co/Cu and Ni/Cu multilayers fabricated by electroplating technique were annealed at various temperatures in order to investigate thermal stability of multilayered structures. Vickers hardness tests on the annealed Co/Cu and Ni/Cu multilayers were conducted at room temperature. It was recognized that after the annealing at 1023K the Co/Cu multilayer still maintained the hardness of as-deposited state. On the other hand, the hardness of Ni/Cu multilayer was almost identical to copper substrate after the annealing at 903K.

Enhanced Formability of Age-Hardenable Aluminium Alloys by Incremental Forming of Solution-Treated Blanks

2013 ◽  
Vol 549 ◽  
pp. 164-171 ◽  
Author(s):  
Amirahmad Mohammadi ◽  
Hans Vanhove ◽  
Albert van Bael ◽  
Joost R. Duflou
Keyword(s):  
Precipitation Hardening ◽  
Incremental Forming ◽  
Natural Aging ◽  
Solution Treated ◽  
Treatment Conditions ◽  
Heat Treated ◽  
Initial Hardness ◽  
Aa 2024 ◽  
Cold Worked ◽  
Pre Treatment

The influence of thermal pre-treatment on the formability of a precipitation-hardening aluminium alloy AA-2024 has been studied for three different heat treatment conditions: annealed (O-temper), solution treated and quenched (W-temper) and solution heat treated, quenched and then cold worked (T-temper).The maximum draw angle has been determined and the geometrical accuracy of specific SPIF formed parts has been compared. It is found that the maximum forming angles of the blank formed in O-temper and W-temper conditions show a respective 41% and 32% increase to those of the T-temper condition (initial blank).The hardness of the material reduces significantly after annealing, while SPIF parts formed from W-temper blanks regain their initial hardness after natural aging.

scholarly journals T4 and T6 Treatment of 6061 Al-15 Vol. % SiCP Composite

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
S. Rajasekaran ◽  
N. K. Udayashankar ◽  
Jagannath Nayak
Keyword(s):  
Room Temperature ◽  
Artificial Aging ◽  
Brinell Hardness ◽  
Natural Aging ◽  
Aging Treatment ◽  
Temperature History ◽  
Peak Hardness ◽  
Aging Behavior ◽  
Hardness Variation ◽  
Peak Aging

Aging temperature history has profound effect on the mechanical and corrosion behavior of 6061 Al/SiC composite. In order to understand the effect of aging on the corrosion resistance, the natural and artificial aging behavior of 15 vol. % 6061 Al-SiCP composites was studied using the aging treatment and the Brinell hardness measurements. The aging curves for the composite (T6 treated) were determined at various aging temperatures such as room temperature, 140, 160, 180, 200, 220, and 240°C. According to the peak hardness variation with temperature profile, it is found that the composite is underaged at 140°C and 160°C. Peak aging takes place at 180°C. Overaging takes place at 200°C, 220°C, and 240°C. The natural aging characteristics of the composite (T4 treated) are also studied using the Brinell hardness measurements.

Relation between Artificial Aging Tests and Natural Aging

1930 ◽  
Vol 3 (1) ◽  
pp. 144-147
Author(s):  
J. M. Bierer ◽  
C. C. Davis
Keyword(s):  
Artificial Aging ◽  
Atmospheric Oxygen ◽  
Natural Aging ◽  
Mechanical Work ◽  
The Other ◽  
Other Hand ◽  
Heat Effects ◽  
Aging Test ◽  
Automobile Tires

Abstract THE more varied the uses to which rubber is put, the more varied are the conditions under which it ages, and the less can it be expected that any single aging test will duplicate these various conditions. The most important factors which promote the deterioration of rubber goods are oxidation by atmospheric oxygen, after-vulcanization, heat effects, cracking and other changes from exposure to sunlight, and wear or deterioration due to mechanical work. No two types of rubber products are exposed in just the same way to these various influences; in fact, one product may be exposed to a marked degree to only one of the influences whereas another may deteriorate from all five influences. Thus, automobile tires undergo oxidation, after-vulcanization, heat effects, cracking from exposure to sunlight and abrasion, and deterioration from mechanical work. On the other hand, steam hose tubes deteriorate predominantly from after-vulcanization and heat effects; oxidation, mechanical work and sunlight playing almost no part. After-vulcanization and oxidation are the most important factors in the deterioration of air-brake hose, while auto-topping and bathing caps undergo severe exposure to sunlight. In brief, each kind of rubber goods is exposed to different conditions, and to attempt to duplicate the different combinations of light, heat, oxygen, and mechanical work would lead to a different test for every type of rubber goods manufactured. Obviously, this is impracticable and undesirable.

Simulation of Natural Aging in Al-Mg-Si Alloys

2015 ◽  
Vol 828-829 ◽  
pp. 468-473 ◽  
Author(s):  
Thomas Weisz ◽  
Piotr Warczok ◽  
Thomas Ebner ◽  
Ahmad Falahati ◽  
Ernst Kozeschnik
Keyword(s):  
Experimental Investigation ◽  
Room Temperature ◽  
Artificial Aging ◽  
Cluster Formation ◽  
Natural Aging ◽  
Room Temperature Aging ◽  
Negative Effect ◽  
Aging Mechanisms ◽  
Microalloying Elements ◽  
Temperature Aging

Natural aging during storage of Al-Mg-Si alloys at room temperature can significantly reduce the maximum strengthening potential (T6) during artificial aging and, therefore, is a key topic in aluminium research and industry. Many different strategies to understand and reduce the negative effect of natural aging have been investigated during the last decades, including analysis of different thermal pre-treatments and considering the effect of different microalloying elements. From these investigations, the vacancy evolution and the formation of clusters containing Mg and Si were found to be the governing aging mechanisms behind natural aging. In this work, we present a model to simulate and predict the behavior of these alloys when subjected to room temperature aging after solutionizing and demonstrate the effects of different thermal routes and chemical composition variations. In the implemented model, the evolution of excess quenched-in vacancies and the effect of solute vacancy traps are considered. Special emphasis is placed on co-cluster formation and its contribution to strengthening. The thermokinetic software MatCalc is used for the simulations and the results of the simulations are validated by experimental investigation.

Behaviour of Artificial Aging in 6066 Alloy Using Microhardness and Nuclear Techniques

2010 ◽  
Vol 305-306 ◽  
pp. 15-22
Author(s):  
Emad A. Badawi ◽  
M.A. Abdel-Rahman ◽  
Alaa El-Deen A. El-Nahhas ◽  
M. Abdel-Rahman
Keyword(s):  
Heat Treatment ◽  
Vickers Hardness ◽  
Artificial Aging ◽  
Solution Treatment ◽  
Natural Aging ◽  
Careful Consideration ◽  
Age Hardening ◽  
Solution Temperature ◽  
Precipitate Size ◽  
Precipitation Heat

Many Aluminum-based alloys are strengthened by using a heat-treatment process known as age-hardening. The aim of this work was to produce a high-strength 6xxx-series Aluminum alloy by adjusting the processing conditions, namely solutionizing and artificial aging. It consists of heating the alloy to a temperature at which the soluble constituents will form an homogeneous mass via solid diffusion, holding the mass at that temperature until diffusion takes place, then quenching the alloy rapidly to retain the homogeneous condition. In the quenched condition, heat-treated alloys are supersaturated solid solutions that are comparatively soft and workable, and unstable, depending upon the composition. After solution treatment and quenching, hardening is achieved either at room temperature (natural aging) or via a precipitation heat treatment at a suitable temperature (artificial aging). Precipitation heat treatments are generally low-temperature, long-term processes. Temperatures range from 115 to 190C; times vary from 5 to 48 h. The choice of time-temperature cycles for precipitation heat treatment should receive careful consideration. The objective is to select the cycle that produces an optimum precipitate size and distribution pattern. The mechanical characterization of heat-treatable 6xxx (Al-Mg-Si-Cu based) 6066 wrought aluminum alloys was studied. Their effects were investigated in terms of microstructure using positron annihilation lifetime techniques and monitoring the mechanical properties by mean of Vickers hardness measurements. The hardness is the resistance of a material to plastic deformation, and gives it the ability to resist deformation when a load is applied. The greater the hardness of the material, the greater resistance it has to deformation. The Vickers hardness of 6066 alloy has its maximum value (98) when aged for (10) hours at (175C) after quenching at 530C; so this temperature is the solution temperature of this alloy .The hardness conformed to reference values.

scholarly journals Influence of Pre-Aging on the Artificial Aging Behavior of a 6056 Aluminum Alloy after Conventional Extrusion

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 385
Author(s):  
Lisa Winter ◽  
Kristin Hockauf ◽  
Mario Scholze ◽  
Ralph Jörg Hellmig ◽  
Thomas Lampke
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Room Temperature ◽  
Artificial Aging ◽  
Solution Treatment ◽  
Natural Aging ◽  
Aging Behavior ◽  
Scanning Calorimetry ◽  
Initial Heat ◽  
Initial Heat Treatment

In the present study, the influence of the initial heat-treatment conditions on the artificial aging behavior after conventional linear extrusion at room temperature was investigated for the precipitation hardening of a 6056 aluminum alloy. A solution-annealed condition was systematically compared to naturally-aged and pre-aged conditions. Differential scanning calorimetry was used for analyzing the precipitation sequence and its dependence on the initial heat treatment. The natural aging behavior prior to extrusion and the artificial aging behavior after extrusion were determined by microhardness measurements as a function of the aging time. Furthermore, the microstructure, dependent on the induced strain, was investigated using optical microscopy and transmission electron microscopy. As a result of pre-aging, following a solid-solution treatment, the formation of stable room-temperature clusters was suppressed and natural aging was inhibited. The artificial aging response after extrusion was significantly enhanced by pre-aging, and the achieved hardness and strength were significantly higher when compared with the equally processed solution-annealed or naturally-aged conditions.

Electron microscope studies of the plastic deformation of ternary alloys based on GaAs

1990 ◽  
Vol 48 (4) ◽  
pp. 1120-1120
Author(s):  
R. Haswell ◽  
U. Bangert ◽  
P. Charsley
Keyword(s):  
Plastic Deformation ◽  
Electron Microscope ◽  
Room Temperature ◽  
Stacking Faults ◽  
The Other ◽  
Ternary Alloys ◽  
Dislocation Mobility ◽  
Semiconducting Materials ◽  
Micro Indentation

A knowledge of the behaviour of dislocations in semiconducting materials is essential to the understanding of devices which use them . This work is concerned with dislocations in alloys related to the semiconductor GaAs . Previous work on GaAs has shown that microtwinning occurs on one of the <110> rosette arms after indentation in preference to the other . We have shown that the effect of replacing some of the Ga atoms by Al results in microtwinning in both of the rosette arms.In the work to be reported dislocations in specimens of different compositions of Gax Al(1-x) As and Gax In(1-x) As have been studied by using micro indentation on a (001) face at room temperature . A range of electron microscope techniques have been used to investigate the type of dislocations and stacking faults/microtwins in the rosette arms , which are parallel to the [110] and [10] , as a function of composition for both alloys . Under certain conditions microtwinning occurs in both directions . This will be discussed in terms of the dislocation mobility.

HAYNES STELLITE ALLOY No. 98M2

Alloy Digest ◽  
1960 ◽  
Vol 9 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
Physical Properties ◽  
Room Temperature ◽  
Base Alloy ◽  
Heat Treating ◽  
The Other ◽  
Stellite Alloy ◽  
Cobalt Base Alloy ◽  
Cobalt Base

Abstract HAYNES STELLITE 98M2 Alloy is a cobalt-base alloy having higher compressive strength and higher hardness than all the other cobalt-base alloys at room temperature and in the red heat range. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength as well as fracture toughness. It also includes information on heat treating, machining, and joining. Filing Code: Co-22. Producer or source: Haynes Stellite Company.

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