Effects of Heat Treatment on a High-Pressure Die-Cast Mg-La-Y Alloy

2011 ◽  
Vol 690 ◽  
pp. 210-213 ◽  
Author(s):  
Serge Gavras ◽  
Su Ming Zhu ◽  
Mark A. Easton ◽  
Mark A. Gibson ◽  
Jian Feng Nie
Keyword(s):  
Heat Treatment ◽  
High Pressure ◽  
Creep Resistance ◽  
Solution Treatment ◽  
Dislocation Motion ◽  
Heat Treatments ◽  
Dimensional Changes ◽  
Heat Treated ◽  
Die Cast ◽  
Solute Atoms

In this study effects of heat treatments on the creep resistance at 177°C/90MPa of a high-pressure die-cast Mg-2.70La-1.50Y (wt.%) alloy were examined. It was found that ageing at 160°C for 24 h (T5) or a solution treatment at 520°C for 1 h (T4) improved creep resistance and caused no blistering on the surface or dimensional changes to the die-cast specimens. TEM was used to characterize the microstructures of heat-treated samples. Improvements to creep resistance might be attributed to the pinning or otherwise retarding of dislocation motion by precipitates and/or solute atoms during creep.

scholarly journals Short Heat Treatments for the F357 Aluminum Alloy Processed by Laser Powder Bed Fusion

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6157
Author(s):  
Matteo Vanzetti ◽  
Enrico Virgillito ◽  
Alberta Aversa ◽  
Diego Manfredi ◽  
Federica Bondioli ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Precipitation Hardening ◽  
Solution Treatment ◽  
Heat Treatments ◽  
Point Of View ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Heat Treated ◽  
Direct Aging

Conventionally processed precipitation hardening aluminum alloys are generally treated with T6 heat treatments which are time-consuming and generally optimized for conventionally processed microstructures. Alternatively, parts produced by laser powder bed fusion (L-PBF) are characterized by unique microstructures made of very fine and metastable phases. These peculiar features require specifically optimized heat treatments. This work evaluates the effects of a short T6 heat treatment on L-PBF AlSi7Mg samples. The samples underwent a solution step of 15 min at 540 °C followed by water quenching and subsequently by an artificial aging at 170 °C for 2–8 h. The heat treated samples were characterized from a microstructural and mechanical point of view and compared with both as-built and direct aging (DA) treated samples. The results show that a 15 min solution treatment at 540 °C allows the dissolution of the very fine phases obtained during the L-PBF process; the subsequent heat treatment at 170 °C for 6 h makes it possible to obtain slightly lower tensile properties compared to those of the standard T6. With respect to the DA samples, higher elongation was achieved. These results show that this heat treatment can be of great benefit for the industry.

scholarly journals Influence of the Solution and Artificial Aging Treatments on the Microstructure and Mechanical Properties of Die-Cast Al–Si–Mg Alloys

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 71
Author(s):  
Ho-Jung Kang ◽  
Jin-Young Park ◽  
Yoon-Suk Choi ◽  
Dae-Hyun Cho
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
Artificial Aging ◽  
Solution Treatment ◽  
Mg Alloys ◽  
Needle Type ◽  
Heat Treated ◽  
Die Cast ◽  
Eutectic Si

Heat treatment is widely used to improve the properties of Al–Si–Mg alloys and its outcomes are influenced by the parameters applied during the treatment. This study describes the effect of the solution and artificial aging treatments on the microstructure and mechanical properties of die-cast Al–Si–Mg alloys. The microstructure of the as-cast Al–Si–Mg alloy was mainly composed of α-Al, complex needle-type eutectic Si particles, Mg2Si, and α-AlFeMn. The complex needle-type eutectic Si particles disintegrated into spheroidal morphologies, while the Mg2Si was dissolved due to the solid solution treatment. The maximum yield strength (YS) and ultimate tensile strength (UTS) values were 126.06 and 245.90 MPa at 520 °C after 90 min of solution heat treatment, respectively. Although the YS and UTS values of the Al–Si–Mg alloys reduced due to the solution treatment, the elongation (EL) of the solid solution heat-treated Al–Si–Mg alloys was improved in comparison to that of the as-cast Al–Si–Mg alloy. The maximum YS and UTS of 239.50 and 290.93 MPa were obtained after performing artificial aging at 180 °C for 180 min, respectively. However, the EL of the aging heat-treated alloy was reduced by a minimal value.

The Heat Treatment of Rheo-High Pressure Die Cast Al-Zn-Mg Alloy 7017

2012 ◽  
Vol 192-193 ◽  
pp. 155-160 ◽  
Author(s):  
Heinrich Möller ◽  
Gonasagren Govender
Keyword(s):  
Heat Treatment ◽  
High Pressure ◽  
Room Temperature ◽  
Artificial Aging ◽  
Solution Treatment ◽  
Mg Alloy ◽  
Aging Response ◽  
Die Cast ◽  
Room Temperature Aging ◽  
Temperature Aging

The CSIR rheocasting system was successfully used to produce high pressure die cast plates of medium-strength, weldable, wrought Al-Zn-Mg alloy 7017. A solution treatment at 450oC for 5 h leads to insufficient dissolution of Mg and Zn, resulting in inadequate T6 mechanical properties after artificial aging. However, a solution treatment at 470oC for 5 h, followed by water quenching and artificial aging at 120oC for 24 h results in tensile properties comparable to those of wrought alloy 7017 plate and extrusions. The alloy also shows a strong room temperature aging response, making it ideal to be used after welding without any further heat treatment.

EFFECT OF HEAT TREATMENTS ON THE MICROSTRUCTURE AND PROPERTIES OF Al/SiCp COMPOSITES PREPARED BY NON-ASSISTED INFILTRATION

2012 ◽  
Vol 1373 ◽  
Author(s):  
R. Martínez-López ◽  
M. I. Pech-Canul ◽  
Z. Chaudhury ◽  
L. A. González
Keyword(s):  
Heat Treatment ◽  
Thermal Stresses ◽  
Solution Treatment ◽  
Heat Treatments ◽  
Peak Hardness ◽  
Maximum Hardness ◽  
X Ray ◽  
Solution Treated ◽  
Hardness Tests ◽  
Heat Treated

ABSTRACTAl/SiCp composites fabricated by the non-assisted infiltration route are attractive materials for various engineering applications. However, the presence of thermal stresses can impair their mechanical properties if they are utilized directly after processing. Therefore, heat treatments are potential solutions to this problem. In this work, the effect of T6-heat-treatment on the microstructure and hardness of Al/50% SiCp composites prepared by the non-assisted infiltration route is investigated. Previous to preform preparation, the SiC powders are coated with colloidal SiO2. Infiltration tests are conducted using two experimental Al-Si-Mg alloys. The composites are sectioned in specimen sizes of 1 cm2 and prepared using standard metallographic procedures. Then they are heat treated performing a solution treatment at 350°C for 3 h and artificial aging at 170°C for 1, 3 and 5 hours. In addition, the specimens are characterized by X-ray diffraction (XRD), optical microscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). They are also characterized in hardness tests, comparing the behavior for the alloy with and without the various treatments. The results show that heat treatments do not affect the matrix/reinforcement interfacial condition and that the undesirable Al4C3 phase is not developed as consequence of thermal treatments. Hardness tests show that for alloy 1 the maximum hardness value is for the solution-heat-treated samples at 350°C and 5 h aging (28.26±4.02 HC); for alloy 2 the maximum hardness is achieved with solution heat treatment at 350°C and 3 h aging (25.86±4.05 HC). For composites processed with alloy1, the maximum hardness is obtained for the solution treated sample at 350 ° C for 3 h (91.8±2.17 HC), whereas for composites processed with alloy 2 the peak hardness is obtained in solution treated samples and aged at 170°C for 1 h (95.2±0.94 HC).

scholarly journals Electron Beam Melting of Ti-6Al-4V Lattice Structures; Correlation between Post Heat Treatment and Mechanical Properties

2021 ◽  
Author(s):  
Giuseppe Del Guercio ◽  
Manuela Galati ◽  
Abdollah Saboori
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Computer Aided Design ◽  
Mechanical Performance ◽  
Industrial Applications ◽  
Heat Treatments ◽  
Layer By Layer ◽  
Lattice Structures ◽  
Heat Treated ◽  
Aided Design

Abstract Additive Manufacturing processes are considered advanced manufacturing methods. It would be possible to produce complex shape components from a Computer-Aided Design model in a layer-by-layer manner. Lattice structures as one of the complex geometries could attract lots of attention for both medical and industrial applications. In these structures, besides cell size and cell type, the microstructure of lattice structures can play a key role in these structures' mechanical performance. On the other hand, heat treatment has a significant influence on the mechanical properties of the material. Therefore, in this work, the effect of the heat treatments on the microstructure and mechanical behaviour of Ti-6Al-4V lattice structures manufactured by EBM was analyzed. The main mechanical properties were compared with the Ashby and Gibson model. It is very interesting to notice that a more homogeneous failure mode was found for the heat-treated samples. The structures' relative density was the main factor influencing their mechanical performance of the heat-treated samples. It is also found that the heat treatments were able to preserve the stiffness and the compressive strength of the lattice structures. Besides, an increment of both the elongation at failure and the absorbed energy was obtained after the heat treatments. Microstructure analysis of the heat-treated samples confirms the increment of ductility of the heat-treated samples with respect to the as-built one.

Mechanical Behaviour of Gas Nitrided Ti6Al4V Bars Produced by Selective Laser Melting

2016 ◽  
Vol 704 ◽  
pp. 225-234 ◽  
Author(s):  
Peter Franz ◽  
Aamir Mukhtar ◽  
Warwick Downing ◽  
Graeme Smith ◽  
Ben Jackson
Keyword(s):  
Heat Treatment ◽  
Selective Laser Melting ◽  
Nitrided Layer ◽  
Xrd Analysis ◽  
Compound Layer ◽  
Processing Parameters ◽  
Heat Treatments ◽  
Laser Melting ◽  
Gas Nitriding ◽  
Heat Treated

Gas atomized Ti-6Al-4V (Ti64) alloy powder was used to prepare distinct designed geometries with different properties by selective laser melting (SLM). Several heat treatments were investigated to find suitable processing parameters to strengthen (specially to harden) these parts for different applications. The results showed significant differences between tabulated results for heat treated billet Ti64 and SLM produced Ti64 parts, while certain mechanical properties of SLM Ti64 parts could be improved by different heat treatments using different processing parameters. Most heat treatments performed followed the trends of a reduction in tensile strength while improving ductility compared with untreated SLM Ti64 parts.Gas nitriding [GN] (diffusion-based thermo-chemical treatment) has been combined with a selected heat treatment for interstitial hardening. Heat treatment was performed below β-transus temperature using minimum flow of nitrogen gas with a controlled low pressure. The surface of the SLM produced Ti64 parts after gas nitriding showed TiN and Ti2N phases (“compound layer”, XRD analysis) and α (N) – Ti diffusion zones as well as high values of micro-hardness as compared to untreated SLM produced Ti64 parts. The microhardness profiles on cross section of the gas nitrided SLM produced samples gave information about the i) microhardness behaviour of the material, and ii) thickness of the nitrided layer, which was investigated using energy dispersive spectroscopy (EDS) and x-ray elemental analysis. Tensile properties of the gas nitrided Ti64 bars produced by SLM under different conditions were also reported.

GENETICAL STUDIES ON MUTANTS IN THE PROGENY OF HEAT-TREATED BARLEY

1937 ◽  
Vol 15c (5) ◽  
pp. 217-229 ◽  
Author(s):  
F. H. Peto
Keyword(s):  
Heat Treatment ◽  
Mutation Rate ◽  
Heat Treatments ◽  
Plastid Mutation ◽  
Heat Treated ◽  
Natural Mutation

Heat treatments were applied to barley seeds and 10 different mutant characters were observed in the progeny, viz.; xantha1 and 2, dwarf1,2,3 and 4, virescent1 and 2, chlorina and albino. Typical Mendelian ratios were not obtained in the first segregating generation owing to the small size of the sector affected in the generation of treatment. In the second and third segregating generations, good fits were obtained in all cases to either monohybrid or dihybrid ratios. Both 3:1 and 15:1 ratios were observed in lines segregating for xantha1 and albino characters. The postulation of the duplicate factor hypothesis was necessary to explain this situation. Chlorina and dwarf mutants segregated in all the cases investigated as simple Mendelian recessives. One virescent strain was believed to have arisen through plastid mutation and was maternally inherited.The heat treatment significantly increased the natural mutation rate for the xantha characters but apparently had no effect on the albino mutation rate. Dwarf, virescent and chlorina mutants were observed in the segregating generation after heat treatment, but were not detected in untreated populations.

Corrosion behavior of heat-treated and cryorolled Al 5052 alloys in different chloride ion concentrations

2020 ◽  
Vol 67 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Anasyida Abu Seman ◽  
Ji Kit Chan ◽  
Muhammad Anas Norazman ◽  
Zuhailawati Hussain ◽  
Dhindaw Brij ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Behaviour ◽  
Solution Treatment ◽  
Chloride Ion ◽  
Optical Microscope ◽  
Al Alloy ◽  
Content Type ◽  
Ion Concentrations ◽  
Heat Treated ◽  
Chloride Environment

Purpose This paper aims to investigate the corrosion behaviour of heat-treated and cryorolled Al 5052 alloys in different Cl− ion concentrations. Design/methodology/approach NaCl solutions with concentrations of 0, 0.5, 3.5 and 5.5 per cent were selected. Samples were subjected to pre-heat treatment (annealing at 300 °C and solution treatment at 540 °C) and cryorolling up to 30 per cent reduction before undergoing corrosion tests. The corrosion behaviour of the samples was then investigated by potentiodynamic polarization. The microstructure of the corroded samples was evaluated under an optical microscope, and the percentages of pits on their surfaces were calculated. Findings The cryorolled samples had a lower corrosion rate than the samples that were not cryorolled. The cryorolled sample that underwent solution treatment showed the highest corrosion resistance among all the samples tested. Practical implications The commercial impact of the study is the possibility of using the cryorolled Al alloy in various ion chloride environment. Originality/value The obtained results help in understanding the corrosion behaviour of cryorolled samples under different heat treatment conditions.

scholarly journals Cyclic Deformation Behavior of A Heat-Treated Die-Cast Al-Mg-Si-Based Aluminum Alloy

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4115
Author(s):  
Sohail Mohammed ◽  
Shubham Gupta ◽  
Dejiang Li ◽  
Xiaoqin Zeng ◽  
Daolun Chen
Keyword(s):  
Heat Treatment ◽  
Strain Amplitude ◽  
Cyclic Deformation ◽  
Stress Amplitude ◽  
Cyclic Hardening ◽  
Life Cycles ◽  
Total Strain ◽  
Total Strain Amplitude ◽  
Heat Treated ◽  
Die Cast

The purpose of this investigation was to study the low-cycle fatigue (LCF) behavior of a newly developed high-pressure die-cast (HPDC) Al-5.5Mg-2.5Si-0.6Mn-0.2Fe (AlMgSiMnFe) alloy. The effect of heat-treatment in comparison with its as-cast counterpart was also identified. The layered (α-Al + Mg2Si) eutectic structure plus a small amount of Al8(Fe,Mn)2Si phase in the as-cast condition became an in-situ Mg2Si particulate-reinforced aluminum composite with spherical Mg2Si particles uniformly distributed in the α-Al matrix after heat treatment. Due to the spheroidization of intermetallic phases including both Mg2Si and Al8(Fe,Mn)2Si, the ductility and hardening capacity increased while the yield stress (YS) and ultimate tensile strength (UTS) decreased. Portevin–Le Chatelier effect (or serrated flow) was observed in both tensile stress–strain curves and initial hysteresis loops during cyclic deformation because of dynamic strain aging caused by strong dislocation–precipitate interactions. The alloy exhibited cyclic hardening in both as-cast and heat-treated conditions when the applied total strain amplitude was above 0.4%, below which cyclic stabilization was sustained. The heat-treated alloy displayed a larger plastic strain amplitude and a lower stress amplitude at a given total strain amplitude, demonstrating a superior fatigue resistance in the LCF regime. A simple equation based on the stress amplitude of the first and mid-life cycles ((Δσ/2)first, (Δσ/2)mid) was proposed to characterize the degree of cyclic hardening/softening (D): D=±(Δσ/2)mid − (Δσ/2)first(Δσ/2)first, where the positive sign “+” represents cyclic hardening and the negative sign “−“ reflects cyclic softening.

Effect of Double-Step Solution Treatment on Rejuvenation Heat Treated Microstructure of IN-738 Superalloy

2020 ◽  
Vol 856 ◽  
pp. 36-42
Author(s):  
Chuleeporn Paa-Rai
Keyword(s):  
Heat Treatment ◽  
Image Analysis ◽  
Electron Microscope ◽  
Solution Treatment ◽  
Single Step ◽  
Double Step ◽  
Heat Treated ◽  
Cast Superalloy ◽  
Scanning Electron

This work investigates the effect of rejuvenation heat treatment, with double-step solution treatment at the temperature from 1150 °C to 1200 °C, on the recovered microstructure of IN-738 cast superalloy. The superalloy has been long-term exposed as a turbine blade in a gas turbine prior to this study. After double solution treatment and aging at 845 °C for 12 h and 24 h, the recovered microstructures were examined by using a scanning electron microscope. Coarse γ΄ particles, that have presented in damaged microstructures, could not be observed in the samples after the rejuvenation heat treatment. In addition, the image analysis illustrates that the reprecipitated γ΄ particles in the samples with double-step solution treatments increase significantly in sizes during aging than that in the samples with the single-step solution treatment. Furthermore, the measurement of the samples hardness presents that the as-receive sample hardness is improved after rejuvenation heat treatment studied in this work.

Sign in / Sign up

Export Citation Format

Share Document