Effect of heat treatment on the mechanical and tribological properties of AA8090/6% SiCp composite

2017 ◽  
Vol 24 (1) ◽  
pp. 129-138
Author(s):  
Amir Kebriyaei ◽  
Seyed Sh. Mirdamadi ◽  
Hassan Saghafian
Keyword(s):  
Heat Treatment ◽  
Wear Mechanism ◽  
Precipitation Hardening ◽  
Rapid Heating ◽  
Research Work ◽  
Wear Test ◽  
Rolling Process ◽  
Age Hardening ◽  
Conventional Heating ◽  
Heat Treated

AbstractAA8090, a certain type of Al-Li alloy, has been widely used in the aerospace industry because of its low density and high strength after heat treatment. In this research work, the AA8090/6% SiCp composite was produced by modified stir casting and then subjected to hot extrusion treatment. One part of the extruded rod was used to prepare the wear test samples and the remaining part was converted to strips with 2 mm thickness via hot rolling process. Three processes, including precipitation hardening with conventional heating, age hardening with rapid heating, and precipitation after directional quenching, were done on samples. The results of the mechanical properties revealed that precipitation hardening after directional quenching reduced the peak of hardness time from 16 to 6 h, increased the peak of hardness by 20%, and improved the tensile strength, yield stress, and elongation by 16%, 16%, and 40%, respectively. The results of wear test indicated that, at the load of 10 N, abrasive wear was the dominant wear mechanism. Increase in load showed delamination, and at the load of 30 N, a transition from mild wear to severe wear occurred due to a change in wear mechanism to adhesive wear. At this load, the samples without heat treatment showed the lowest wear rate in comparison to the samples subjected to heat treatment. By and large, the specimens heat treated with directional quenching among the other heat-treated specimens showed the higher wear resistance at all of loads.

Comparison of Microstructure and Mechanical Properties of Additively Manufactured and Conventional Maraging Steel

2020 ◽  
Vol 405 ◽  
pp. 133-138
Author(s):  
Ludmila Kučerová ◽  
Andrea Jandová ◽  
Ivana Zetková
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Maraging Steel ◽  
Precipitation Hardening ◽  
High Strength ◽  
Hardness Measurement ◽  
Nickel Steel ◽  
Heat Treated ◽  
Good Material ◽  
Iron Nickel

Maraging steel is an iron-nickel steel alloy, which achieves very good material properties like high toughness, hardness, good weldability, high strength and dimensional stability during heat treatment. In this work, maraging steel 18Ni-300 was manufactured by selective laser melting. It is a method of additive manufacturing (AM) technology, which produces prototypes and functional parts. Sample of additively manufactured and conventional steel with the same chemical composition were tested after in three different states – heat treated (as-built/as-received), solution annealed and precipitation hardened. Resulting microstructures were analysed by light and scanning electron microscopy and mechanical properties were obtained by hardness measurement and tensile test. Cellular martensitic microstructures were observed in additively manufactured samples and conventional maraging steel consisted of lath martensitic microstructures. Very similar mechanical properties were obtained for both steels after the application of the same heat treatment. Ultimate tensile strengths reached 839 – 900 MPa for samples without heat treatment and heat treated by solution annealing, the samples after precipitation hardening had tensile strengths of 1577 – 1711 MPa.

Precipitate and Age Hardening Response of As-Cast Mg-8Yb-0.5Zr Magnesium Alloy

2011 ◽  
Vol 399-401 ◽  
pp. 17-20
Author(s):  
Wen Bin Yu ◽  
Zhi Qian Chen ◽  
Mang Zhang ◽  
Zhou Yu
Keyword(s):  
Heat Treatment ◽  
Magnesium Alloy ◽  
Grain Boundaries ◽  
Microstructure Evolution ◽  
Solution Heat Treatment ◽  
Artificial Aging ◽  
Precipitation Hardening ◽  
Intermetallic Phase ◽  
Age Hardening ◽  
Maximum Hardness

The precipitation hardening response of as-cast Mg-8Yb-0.5Zr magnesium alloy was investigated in the present work. The microstructure evolution of the alloy illustrated that Mg2Yb intermetallic phase was dissolved by solution heat treatment at 520°C for 12 hours. An apparent precipitation hardening response in Mg-8Yb-0.5Zr was discovered after artificial aging at 150°C, with maximum hardness increment of about 80 percent at the peak condition. It was found that the precipitates of the alloy were in the shape of two conjoined cosh and globe about 50 nm, and precipitated preferentially on grain boundaries and dislocations.

scholarly journals Effects of Post Heat Treatment on the Mechanical Properties of Cold-Rolled Ti/Cu Clad Sheet

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1672
Author(s):  
Chang-Suk Youn ◽  
Dong-Geun Lee
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Rolling Process ◽  
Post Treatment ◽  
Post Heat Treatment ◽  
Clad Sheet ◽  
Heat Treated ◽  
Bonding Properties ◽  
High Elongation ◽  
Cold Rolled

Titanium and titanium alloys have excellent corrosion and heat resistance, but weak electric and thermal conductivity. The weak conductivity of titanium can be overcome by cladding with copper, which has high conductivity. Although titanium is expensive, it is selected as a material suitable for applications requiring corrosion resistance such as in heat exchangers. This study was to investigate the effect of post heat treatment on the mechanical properties of the Ti/Cu cold-rolled clad plate by using the interfacial diffusion bonding. A titanium clad by cold rolling should be heat-treated after the rolling process to improve the bonding properties through the diffusion of metals and removal of residual stress due to work hardening, despite the easy formation of intermetallic compounds of Ti and Cu. As a result post-treatment, the elongation was improved by more than two times from 21% to max. 53% by the Ti-Cu interface diffusion phenomenon and the average tensile strength of the 450 °C heat-treated specimens was 353 MPa. By securing high elongation while maintaining excellent tensile and yield strength through post-treatment, the formability of Ti-Cu clad plate can be greatly improved.

scholarly journals Microstructure of laser metal deposited duplex stainless steel: Influence of shielding gas and heat treatment

2020 ◽  
Author(s):  
Maria Asuncion Valiente Bermejo ◽  
Karthikeyan Thalavai Pandian ◽  
Björn Axelsson ◽  
Ebrahim Harati ◽  
Agnieszka Kisielewicz ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Nitrogen Loss ◽  
Steel Wire ◽  
Research Work ◽  
Shielding Gas ◽  
Austenite Content ◽  
Heat Treated ◽  
Phase Balance

AbstractThis research work is the first step in evaluating the feasibility of producing industrial components by using Laser Metal Deposition with duplex stainless steel Wire (LMDw). The influence of Ar and N2 shielding gases was investigated in terms of nitrogen loss and in the microstructure and austenite content of different deposited geometries. The evolution of the microstructure in the build-up direction of the Ar and N2-shielded blocks was compared in the heat-treated and as-deposited conditions. The susceptibility for oxygen pick-up in the LMDw deposits was also analyzed, and oxygen was found to be in the range of conventional gas-shielded weldments. Nitrogen loss occurred when Ar-shielding was used; however, the use of N2-shielding prevented nitrogen loss. Austenite content was nearly doubled by using N2-shielding instead of Ar-shielding. The heat treatment resulted in an increase of the austenite content and of the homogeneity in the microstructure regardless of the shielding gas used. The similarity in microstructure and the low spread in the phase balance for the as-deposited geometries is a sign of having achieved a stable and consistent LMDw process in order to proceed with the build-up of more complex geometries closer to industrial full-size components.

scholarly journals The Influence of Post-Heat-Treatments on the Tensile Strength and Surface Hardness of Selective Laser Melted AlSi10Mg

2017 ◽  
Vol 370 ◽  
pp. 171-176 ◽  
Author(s):  
Leonhard Hitzler ◽  
Amandine Charles ◽  
Andreas Öchsner
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Precipitation Hardening ◽  
Elevated Temperatures ◽  
Surface Hardness ◽  
Heat Treatments ◽  
Age Hardening ◽  
Material Strength ◽  
Post Heat Treatment ◽  
Treatment Procedure

Recent investigations revealed major fluctuations in the material properties of selective laser melted AlSi10Mg, which corresponded with the varying precipitation-hardening state of the microstructure, caused by the differing dwell times at elevated temperatures. It was indicated that a subsequent heat treatment balances the age-hardening and results in a homogenized material strength. In order to further investigate this statement selective laser melted AlSi10Mg samples were subject to multiple post-heat-treatments. Subsequently, the surface hardness and tensile strength was determined and compared with the as-built results. The post-heat-treatment led to an arbitrary occurrence of rupture, indicating a successful homogenization, coupled with a remarkable improvement in ductility, but to the costs of a lowered tensile strength, which was highly dependent on the chosen heat-treatment procedure.

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.

TEXTURE AND FORMABILITY DEVELOPMENT OF ASYMMETRY ROLLED AA 3003 AL ALLOY SHEET

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5895-5900 ◽  
Author(s):  
INSOO KIM ◽  
SAIDMUROD AKRAMOV ◽  
HAE BONG JEONG
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Plastic Strain ◽  
Research Work ◽  
Heat Treating ◽  
Alloy Sheet ◽  
Al Alloy ◽  
Fine Grain ◽  
Heat Treated ◽  
Crystallographic Orientations

The physical, mechanical properties and formability of sheet metal depend on preferred crystallographic orientations (texture). In this research work, we investigated texture development and formability of AA 3003 aluminum alloy sheets after asymmetry rolling and subsequent heat treatment. After asymmetry rolling, the specimens showed fine grain size. We also investigated the change of the plastic strain ratios after asymmetry rolling and subsequent heat-treating condition. The plastic strain ratios of asymmetrically rolled and subsequent heat treated samples are 1.5 times higher than the initial AA 3003 Al alloy sheets. These could be attributed to the formation of ND//<111> texture component through asymmetry rolling in Al sheet.

Precipitation Hardening in Al-Cu-Mg Alloys: Analysis of Precipitates, Modelling of Kinetics, Strength Predictions

2006 ◽  
Vol 519-521 ◽  
pp. 251-258 ◽  
Author(s):  
Marco J. Starink ◽  
J.L. Yan
Keyword(s):  
Precipitation Hardening ◽  
Rapid Heating ◽  
Solution Treatment ◽  
Treatment Temperature ◽  
S Phase ◽  
Age Hardening ◽  
Solution Treatment Temperature ◽  
Hardening Mechanism ◽  
Mechanism Model ◽  
Constitutive Components

In Al-Cu-Mg with compositions in the α+S phase field, precipitation hardening is a twostage process. Experimental evidence shows that the main precipitation sequence in alloys with Cu contents in excess of 1wt% is involves Cu-Mg co-clusters, GPBII/S'' and S. The first stage of the age hardening is due to the formation of Cu-Mg co-clusters, and the hardening can be modelled well by a modulus hardening mechanism. The appearance of the orthorhombic GPBII/S'' does not influence the hardness. The second stage of the hardening is due to the precipitation of S phase, which strengthens the alloy predominantly through the Orowan looping mechanism. These findings are incorporated into a multi-phase, multi mechanism model for yield strength of Al-Cu-Mg based alloys. The model is applied to a range of alloys with Cu:Mg ratios between 0.1 and 1 and to heat treatments ranging from room temperature ageing and artificial isothermal ageing to rapid heating to the solution treatment temperature. The predictive capabilities of this model are reviewed and its constitutive components are compared and contrasted with a range of other methods, such as the Kampmann-Wagner and JMAK models for precipitation as well as the LSW model for coarsening.

Microstructural and Vickers Microhardness Evolution of Heat Treated Secondary Aluminium Cast Alloy

2013 ◽  
Vol 586 ◽  
pp. 137-140 ◽  
Author(s):  
Lenka Hurtalová ◽  
Eva Tillová ◽  
Mária Chalupová
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Artificial Aging ◽  
Vickers Microhardness ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Holding Time ◽  
Age Hardening ◽  
Structural Components ◽  
Heat Treated

Secondary aluminium alloys are made out of aluminium scrap and aluminium-processable waste by recycling. These alloys contain different alloying elements such as Al, Cu, Fe, Si and Mg that form intermetallic phases in aluminium matrix and influence on the microstructure, basic mechanical properties and microhardness evolution in aluminium cast alloy. As experimental material was used secondary aluminium cast alloy AlSi9Cu3. Material was subjected to heat treatment (age-hardening) consisting of a solution treatment at temperature 515 °C with holding time 4 hours, than water quenching at 40 °C and artificial aging by different temperature 130 °C, 150 °C and 170 °C with different holding time (2, 4, 8, 16 and 32 hours). The age-hardening led to changes in the morphology of structural components, but also leads to precipitation of finer hardening phases in the material substructure. As optimal age-hardening mode for secondary aluminium cast alloy AlSi9Cu3 was determined mode consisting of solution treatment at temperature 515 °C with holding time 4 hours and artificial aging at temperature 170 °C with holding time 16 hours. After this heat treatment cast alloy shows the best changes in microstructure and mechanical properties. These changes are comparable with changes by primary AlSi9Cu3 cast alloy.

scholarly journals A New Infrared Heat Treatment on Hot Forging 7075 Aluminum Alloy: Microstructure and Mechanical Properties

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1177 ◽  
Author(s):  
Yi-Ling Chang ◽  
Fei-Yi Hung ◽  
Truan-Sheng Lui
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
High Temperature ◽  
Material Property ◽  
Rapid Heating ◽  
Hot Forging ◽  
Target Material ◽  
Age Hardening ◽  
Experimental Result ◽  
7075 Aluminum Alloy

When hot forging 7075 aluminum alloy, as a military material durable enough for most of its applications, it needs to be heat-treated to ensure the target material property achieves the application requirements. However, the material properties change because of heat throughout usage. In this study, a new approach was devised to heat treat the alloy to prevent material property changes. The study further clarified the effect of rapid heat treatment on the high-temperature resistance of a hot forging 7075 aluminum alloy. Infrared (IR) heat treatment was used as a rapid heating technique to effectively replace the conventional resistance heat (RH) treatment method. Our experimental result showed that IR heat treatment resulted in better age hardening at the initial aging stage, where its tensile strength and elongation appeared like that of a resistance heat treatment. More so, based on hardness and tensile test results, the IR-heated treatment process inhibited the phase transformation of precipitations at a higher temperature, improving high-temperature softening resistance and enhancing the thermal stability of the hot forging 7075 aluminum alloy.

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