Solution Heat Treatment and Cold Die Quenching in Forming AA 6xxx Sheet Components: Feasibility Study

2005 ◽  
Vol 6-8 ◽  
pp. 673-680 ◽  
Author(s):  
R.P. Garrett ◽  
J. Lin ◽  
Trevor A. Dean
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Treatment Time ◽  
Hot Stamping ◽  
Mechanical Tests ◽  
Forming Process ◽  
Quenching Rate ◽  
Die Quenching ◽  
Combined Solution

To overcome the major problems in forming aluminium sheet components, such as springback, low formability and microstructure variation a novel process is proposed in this paper. That is combined Solution Heat Treatment (SHT) hot stamping followed by cold die quenching. To determine the feasibility of such process a series of thermal-mechanical tests have been designed and carried out on aluminium alloy AA6082. Three aspects of the forming process are investigated and represented in the paper. The first is to investigate the effects of SHT proportions on the mechanical properties of the material. The second is the effects of quenching rates on the mechanical properties after SHT. The third is the effect of predeformation after the SHT and the quenching rate on the mechanical properties of the formed parts. Summaries are given for each aspect of the study. These tests are to investigate the effects of Solution Heat Treatment time proportion. Variables are also introduced during the cold die quenching, including clearance between the testpiece and dies as well as the applied load. Finally the relationship between quench rate and predeformation is investigated.

scholarly journals Selection of optimal solution heat treatment of the casting cylinder heads

2018 ◽  
Vol 157 ◽  
pp. 02053 ◽  
Author(s):  
Eva Tillová ◽  
Mária Chalupová ◽  
Lenka Kuchariková ◽  
Juraj Belan ◽  
Denisa Závodská
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Treatment Time ◽  
Crack Nucleation ◽  
Particle Density ◽  
Solution Treatment ◽  
Optimal Solution ◽  
Solution Temperature ◽  
Selection Of

The effect of solution treatment on mechanical properties (UTS, elongation, Brinell hardness) and microstructure (Si-morphology and Si-size) of an aluminium alloy (A356) used for casting cylinder heads was studied. The tests were carried out with specimens machined from the bulkheads of V8 engine blocks cast by the low pressure process. The samples were tested in as-cast and T6 heat treating conditions (solution heat treatment at 530°C with different time - 2, 3, 4, 5, 6, 7 hours, quenching in water at 20°C and precipitation hardened for 4 hour at 160°C). The results show that used heat treatment improves mechanical properties of the cylinder head casts. Tensile strength and hardness of specimens increase with solution treatment time. The hardness is a reflection of solution strengthening and silicon particle distribution in matrix. Solution temperature 530°C and 5 hours solution time is appropriate to obtain better morphology and distribution of Si particles in microstructure. Prolonged solution treatment (more than 5 hours) leads to a coarsening of the Si particles, while the numerical Si density decreases. As the particle density decreases, a fewer number of sites are available for crack nucleation, and hence, the fracture properties are improved. The data obtained from this study will be used to improve process control, and to help the selection of heat treatment of the casting for future products.

scholarly journals High Mechanical Properties of AZ91 Mg Alloy Processed by Equal Channel Angular Pressing and Rolling

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 386 ◽  
Author(s):  
Yuchun Yuan ◽  
Qingfang Guo ◽  
Jiapeng Sun ◽  
Huan Liu ◽  
Qiong Xu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Solution Heat Treatment ◽  
High Strength ◽  
Mg Alloy ◽  
Angular Pressing ◽  
Wrought Magnesium Alloy ◽  
Combined Solution

Mechanical properties usually take precedence for wrought magnesium alloy when it would be used as a structure material. This paper proposed an approach that achieved high strength in AZ91 Mg alloy. The main procedure combined solution heat treatment, equal channel angular pressing (ECAP), and the subsequent low temperature rolling. After solution heat treatment and ECAP, the alloy had fine grains and excellent ductility, which benefited the following rolling at low temperature. By the following rolling (at 150 °C), the strength was further increased to ~432 MPa with a moderate ductility. This approach was proved effective in refining the grains and accumulating dislocations. The ultrahigh strength was attributed to the high density of dislocations and fine structure. The uniformly distributed fine precipitates also supplied precipitate hardening. Recrystallization that happened during rolling and annealing was the main reason for the moderate ductility.

The Effect of Aging Heat Treatment on the Microstructure and Mechanical Properties of 10Cr20Ni25Mo1.5NbN Austenitic Steel

2016 ◽  
Vol 35 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Zhiyuan Liang ◽  
Wanhua Sha ◽  
Qinxin Zhao ◽  
Chongbin Wang ◽  
Jianyong Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Austenitic Steel ◽  
Treatment Time ◽  
Aging Treatment ◽  
Secondary Phases ◽  
Aging Heat Treatment ◽  
Microstructure And Mechanical Properties ◽  
The Impact

AbstractThe effect of aging heat treatment on the microstructure and mechanical properties of 10Cr20Ni25Mo1.5NbN austenitic steel was investigated in this article. The microstructure was characterized by scanning electron microscopy, energy dispersive spectrometry and transmission electron microscopy. Results show that the microstructure of 10Cr20Ni25Mo1.5NbN austenitic is composed of austenite. This steel was strengthened by precipitates of secondary phases that were mainly M23C6 carbides and NbCrN nitrides. As aging treatment time increased, the tensile strength first rose (0–3,000 h) and then fell (3,000–5,000 h) due to the decrease of high density of dislocations. The impact absorbed energy decreased sharply, causing the sulfides to precipitate at the grain boundary. Therefore, the content of sulfur should be strictly controlled in the steelmaking process.

Application of Tailored Heat Treated Blanks under Quasi Series Conditions

2007 ◽  
Vol 344 ◽  
pp. 383-390 ◽  
Author(s):  
Marion Merklein ◽  
Uwe Vogt
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Local Heat ◽  
Strength Distribution ◽  
Process Window ◽  
Short Term ◽  
Forming Process ◽  
Heat Treated ◽  
Set Up ◽  
The Impact

Tailored Heat Treated Blanks (THTB) are blanks that exhibit locally different strength specifically optimized for the succeeding forming process. The strength distribution is set by a local, short-term heat treatment modifying the mechanical properties of the material. Hence, THTB allow enhancing forming limits significantly leading to shorter and more robust manufacture process chains. In order to qualify the use of THTB under quasi series conditions, the interdependencies of the blank’s local heat treatment and the entire process chain of the car body manufacture have to be analyzed. In this respect, the impact of a short-term heat treatment on the mechanical properties of AA6181PX, a commonly used aluminum alloy in today’s car bodies, was studied. Also the influence of a short-term heat treatment on the coil lubricant, usually already applied by the material supplier, was given a closer look. Based on these experiments process restrictions for the application of THTB in an industrial automotive environment were derived and a process window for the THTB design was set up. In conclusion, strategies were defined how to enhance the found process boundaries leading to a more robust process window.

Study of Cu Addition on Precipitation Behaviors and Mechanical Properties in AA6082 Al-Mg-Si Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 825-828 ◽  
Author(s):  
Man Jin ◽  
Jing Li ◽  
Guang Jie Shao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Thermal Stability ◽  
Treatment Process ◽  
Mechanical Tests ◽  
Age Hardening ◽  
Heat Treatment Process ◽  
Softening Process

The precipitation behaviors and microstructures of nano-precipitates in AA6082 Al-Mg-Si alloy with and without Cu additions during heat treatment process were studied using hardness measurements, TEM, mechanical tests and 3DAP. Meanwhile, the softening process of 6082 alloys with Cu and without Cu, isothermally conditioned at 250°C, has also been investigated. It was found that the rate of age hardening, mechanical properties and thermal stability are higher for the Cu-containing alloy. The TEM and 3DAP observations showed that Q’ precipitates were existed after aged at 170°C for 8h in the alloy with Cu addition. Comparing the hardness, mechanical properties and thermal stability curves, it was concluded that the Q’ precipitates play a major role in improving the age hardening kinetics and properties of 6082 alloy with Cu addition.

Development and Characterization of New Ti-25Ta-Zr Alloys for Biomedical Applications

2021 ◽  
Vol 1016 ◽  
pp. 137-144
Author(s):  
Pedro Akira Bazaglia Kuroda ◽  
Fernanda de Freitas Quadros ◽  
Mycaela Vieira Nascimento ◽  
Carlos Roberto Grandini
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Elastic Modulus ◽  
Biomedical Applications ◽  
Solution Heat Treatment ◽  
High Hardness ◽  
Microstructural Characterization ◽  
Β Phase ◽  
Cp Ti ◽  
Microscopy Techniques

This paper deals with the study of the development, structural and microstructural characterization and, selected mechanical properties of Ti-25Ta-50Zr alloy for biomedical applications. The alloy was melted in an arc furnace and various solution heat treatments were performed to analyze the influence of the temperature and time on the structure, microstructure, microhardness and elastic modulus of the samples. The structural and microstructural results, obtained by X-ray diffraction and microscopy techniques, showed that the solution heat treatment performed at high temperatures induces the formation of the β phase, while solution heat treatment performed at low temperatures induces the formation of the α” and ω metastable phases. Regarding the effect of time, samples subjected to heat treatment for 6 hours have only the β phase, indicating that lengthy treatments suppress the α” phase. Regarding the hardness and elastic modulus, the alloy with the α” and ω phases, after treatment performed at a temperature of 500 °C, has a high hardness value and elastic modulus due to the presence of the ω phase that hardens and weakens alloys. The titanium alloys developed in this study have excellent mechanical properties results for use in the orthopedic area, better than many commercial materials such as cp-Ti, stainless steel and Co-Cr alloys.

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