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.

scholarly journals Aging Response and Precipitation Behavior after 5% Pre-Deformation of an Al-Mg-Si-Cu Alloy

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1422 ◽  
Author(s):  
Shuoxun Jin ◽  
Tungwai Ngai ◽  
Liejun Li ◽  
Shian Jia ◽  
Tongguang Zhai ◽  
...  
Keyword(s):  
Yield Strength ◽  
Artificial Aging ◽  
Natural Aging ◽  
Negative Influence ◽  
Peak Hardness ◽  
Cu Alloy ◽  
Transmission Electron ◽  
Peak Aging ◽  
Peak Aged ◽  
Deformation Treatment

In this study, Al-1.00 Mg-0.65 Si-0.24 Cu alloy was solution heat-treated, water-quenched, and then pre-deformed for 5% before aging. The peak hardness and yield strength of the pre-deformed sample with subsequent artificial aging were similar to that of a T6 condition sample. It was also found that the pre-deformation treatment could inhibit the negative influence of natural aging to some degree. After seven days of natural aging, the pre-deformed sample obtained better peak hardness and yield strength upon artificial aging than the sample without pre-deformation. In addition, the pre-deformation treatment could reduce 50% of the artificial aging time to reach the peak aging condition compared with T6 treatment. For the peak aged condition in the pre-deformed sample, transmission electron microscopy (TEM) observation found two types of precipitates exhibited along the dislocations besides the β″ precipitates in the Al matrix. Both precipitates had disordered atomic arrangements on the ordered subcell (Si network). The disordered precipitates occupied a number of Mg and Si atoms, resulting in less β″ precipitates formed during artificial aging at 180 °C.

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.

Aging Property of AZ91D Magnesium Alloy Screw Thread-Rolled at Room Temperature Using Extrusion-Torsion Simultaneous Processing

2016 ◽  
Vol 879 ◽  
pp. 2450-2455
Author(s):  
Mitsuaki Furui ◽  
Shouyou Sakashita ◽  
Shougo Suzuki ◽  
Tetsuo Aida ◽  
Yuusuke Ishisaka ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Room Temperature ◽  
Aging Treatment ◽  
High Strength ◽  
Extrusion Process ◽  
Peak Hardness ◽  
Screw Thread ◽  
Az91d Magnesium Alloy ◽  
Simultaneous Processing ◽  
Aging Property

We have proposed a new extrusion process functionally combined with torsion. Extrusion-torsion simultaneous processing is a very attractive technique for fabricating a rod-shape material with high strength and excellent workability. To improve the hardness, the aging treatment was performed with AZ91D magnesium alloy screw thread-rolled at room temperature using extrusion-torsion simultaneous processing. The distribution of hardness from the tip to center in as thread-rolled screw was modified to uniform distribution by the isothermal aging treatment at 423 K for 460.8 ks. The peak hardness was not depended on the working temperature and rotation speed during extrusion-torsion simultaneous processing. β-Mg17Al12 precipitates are obviously grown in as peak-aged condition comparing with as thread-rolled condition.

scholarly journals Effects of natural aging and reversion treatments on artificial aging behavior of 6000 series aluminum alloys

2009 ◽  
Vol 59 (3) ◽  
pp. 128-133 ◽  
Author(s):  
Takahiko Nakamura ◽  
Kazuto Morita ◽  
Masanori Nagai ◽  
Shin-ya Komatsu
Keyword(s):  
Aluminum Alloys ◽  
Artificial Aging ◽  
Natural Aging ◽  
Aging Behavior

Nano-Scale Clusters Formed in the Early Stage of Phase Decomposition of Al-Mg-Si Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 357-360 ◽  
Author(s):  
Shoichi Hirosawa ◽  
Tatsuo Sato
Keyword(s):  
Early Stage ◽  
Sheet Material ◽  
Three Dimensional ◽  
Natural Aging ◽  
Aging Treatment ◽  
Atom Probe ◽  
Phase Decomposition ◽  
Aging Behavior ◽  
Scanning Calorimetry ◽  
Nano Scale

The formation of nano-scale clusters (nanoclusters) prior to the precipitation of the strengthening b” phase significantly influences two-step aging behavior of Al-Mg-Si alloys. In this work, the existence of two kinds of nanoclusters has been verified in the early stage of phase decomposition by differential scanning calorimetry (DSC) and three-dimensional atom probe (3DAP). Pre-aging treatment at 373K before natural aging was also found to form preferentially one of the two nanoclusters, resulting in the remarkable restoration of age-hardenability at paint-bake temperatures. Such microstructural control by means of optimized heat-treatments; i.e. nanocluster assist processing (NCAP), possesses great potential for enabling Al-Mg-Si alloys to be used more widely as a body-sheet material of automobiles.

Isochronal Aging Hardening of the Mg-8Gd-3Y-0.5Zr Alloy after Cold Rolling

2013 ◽  
Vol 747-748 ◽  
pp. 333-339
Author(s):  
Yan Cai Xie ◽  
De Jiang Li ◽  
Xiao Qin Zeng ◽  
Xin Su ◽  
Wen Jiang Ding ◽  
...  
Keyword(s):  
Cold Rolling ◽  
Heating Rate ◽  
Aging Process ◽  
Room Temperature ◽  
Peak Hardness ◽  
Heating Rates ◽  
Hardening Law ◽  
Transmission Electron ◽  
Peak Aging ◽  
Aging Hardening

By transmission electron microscopy (TEM) and optical microscopy (OM), the isochronal aging hardening law and microstructure have been studied for the Mg-8Gd-3Y-0.5Zr alloy after cold rolling. During isochronal aging process (heated from room temperature to 500 with the heating rate of 1/min), there are two peak hardness temperature points, which are corresponding to the large number of precipitation of β and β phases, and the peak aging time of the alloy substantially decreased with the increase of deformation reduction. The β phases started to precipitate at temperatures of 145, 134, 127 and 124 in the alloy after cold rolling with the reduction of 0%, 8%, 15% and 22%. The heating rate greatly affected the starting precipitation of metastable phases. β phases started to precipitate at temperatures of 109 and 124 with the reduction of 22% and with the heating rates of 3 /min and 30 /min.

Study of a Formability Process Chain for a Copper-Free Al-Zn-Mg-Alloy by a Retrogression and Re-Aging Treatment (RRA)

2013 ◽  
Vol 549 ◽  
pp. 295-301 ◽  
Author(s):  
N. Jaburek ◽  
Marion Merklein
Keyword(s):  
Flow Curve ◽  
Room Temperature ◽  
Natural Aging ◽  
Aging Treatment ◽  
Mg Alloy ◽  
Strain Hardening Exponent ◽  
Process Chain ◽  
Cold Forming ◽  
Time Treatment ◽  
Short Time

The material for the experiment was a copper-free Al-Zn-Mg-alloy. Because of natural aging after solution treating these materials are not storable at room temperature in T4 temper. Therefore 7xxx series Al alloys are mainly delivered in an artificially aged T6 temper. This state is not proper for a cold formability process, a thermal formability processes like hot working has to be use. In this paper a process chain based on so-called retrogression and re-aging (RRA) treatment was investigated to allow cold forming after a short time treatment. To achieve this tensile test specimens were tested under various retrogression temperatures (220 - 360 °C) and at times (1 - 7 min) to evaluate the flow curve. The properties like strain hardening exponentnand strength coefficientCof the Ludwik-Hollomon equation, a common approximation of the flow curve, are illustrated and the influence of the process parameter is discussed. A re-aging treatment at 130 °C for 16 h after retrogression of non-deformed and deformed material is also examined.

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.

scholarly journals Peening Natural Aging of Aluminum Alloy by Ultra-High-Temperature and High-Pressure Cavitation

2021 ◽  
Vol 11 (7) ◽  
pp. 2894
Author(s):  
Toshihiko Yoshimura ◽  
Masayoshi Iwamoto ◽  
Takayuki Ogi ◽  
Fumihiro Kato ◽  
Masataka Ijiri ◽  
...  
Keyword(s):  
Residual Stress ◽  
High Pressure ◽  
Aluminum Alloy ◽  
High Temperature ◽  
Compressive Residual Stress ◽  
Artificial Aging ◽  
Solution Treatment ◽  
Natural Aging ◽  
Aging Treatment ◽  
Ultra High Temperature

The peening solution treatment was performed on AC4CH aluminum alloy by ultra-high-temperature and high-pressure cavitation (UTPC) processing, and the peening natural aging was examined. Furthermore, peening artificial aging treatment by low-temperature and low-pressure cavitation (LTPC) was performed, and the time course of peening natural aging and peening artificial aging were compared and investigated. It was found that when the AC4CH alloy is processed for an appropriate time by UTPC processing, compressive residual stress is applied and natural aging occurs. In addition, the UTPC processing conditions for peening natural aging treatment with high compressive residual stress and surface hardness were clarified. After peening artificial aging by LTPC processing, the compressive residual stress decreases slightly over time, but the compression residual stress becomes constant by peening natural aging through UTPC treatment. In contrast, it was found that neither natural nor artificial peening natural aging occurs after processing for a short time.

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