The Changes of Fatigue Properties in Aluminium Cast Alloy during Solution Treatment

2013 ◽  
Vol 592-593 ◽  
pp. 433-436 ◽  
Author(s):  
Lenka Hurtalová ◽  
Eva Tillová ◽  
Mária Chalupová
Keyword(s):  
Fatigue Test ◽  
Cast Alloy ◽  
Eutectic Silicon ◽  
Testing Machine ◽  
Solution Treatment ◽  
Natural Aging ◽  
Load Ratio ◽  
Fatigue Properties ◽  
Area Reduction ◽  
Different Temperatures

This paper describes the effect of solution treatment on the fatigue properties of AlSi9Cu3 cast alloy. The heat treatment consisted of a solution treatment at two different temperatures 515°C and 525°C, a holding time of 4 hours; water quenching at 40°C and natural aging at room temperature for 24 hours. Thus prepared samples were subjected to fatigue test with a rotating bending loading (testing machine ROTOFLEX operating at 30 Hz, load ratio R = -1). The fatigue fracture surfaces were observed using a scanning electron microscope (SEM) after the fatigue test. The results showed that the existence of casting defects (8.4 % of micro-shrinkage) has considerable influence on fatigue properties and can be considered as fatigue crack initiators in what leads to final fatigue damage. Apart from cast defects, the morphology of eutectic silicon and intermetallic phases (Fe- and Cu-rich phases) are also important factors which have an influence on the fatigue properties of Al-Si cast components. The solution treatment used (at 525°C/4hours) has increased fatigue properties (the fatigue lifetime increased from 49 to 76 MPa), thanks to Si particles, morphology changes, and cast defects area reduction as well as reduction Fe-rich phases.

Study of Artificial Aging Temperature Effect on Morphology of Structural Parameters in Aluminium Cast Alloy

2017 ◽  
Vol 891 ◽  
pp. 354-359
Author(s):  
Lenka Kuchariková ◽  
Eva Tillová ◽  
Mária Chalupová ◽  
Juraj Belan ◽  
Ivana Švecová ◽  
...  
Keyword(s):  
Artificial Aging ◽  
Cast Alloy ◽  
Structural Parameters ◽  
Eutectic Silicon ◽  
Solution Treatment ◽  
Analytical Techniques ◽  
Intermetallic Phases ◽  
Holding Time ◽  
Different Temperatures ◽  
Alloy Microstructure

The contribution describes changes in morphology of structural parameters in recycled (secondary) AlSi9Cu3 cast alloy microstructure. These changes depended on different temperatures of artificial aging. The T6 heat treatment, which was used for affecting the structural parameters morphology, consisted of solution treatment at temperature 515 °C with holding time 4 hours, water quenching at 40°C and artificial aging at different temperatures 130 °C, 150 °C, 170 °C, 190 °C and 210 °C with different holding time 2, 4, 8, 16 and 32 hours. The morphology of structural parameters was observed using combination of different analytical techniques (light microscopy upon black-white and colour etching, scanning electron microscopy - SEM upon deep etching). The different temperatures of artificial aging led to changes in microstructure include the spheroidization and coarsening of eutectic silicon, gradual disintegration, shortening and thinning of Fe-rich intermetallic phases, the dissolution of precipitates and the precipitation of finer hardening phase (Al2Cu).

Identification and Analysis of Intermetallic Phases in Age-Hardened Recycled AISi9Cu3 Cast Alloy

2012 ◽  
Vol 59 (4) ◽  
pp. 385-396 ◽  
Author(s):  
Lenka Hurtalová ◽  
Eva Tillová ◽  
Mária Chalupová
Keyword(s):  
Tensile Strength ◽  
Automotive Industry ◽  
Cast Alloy ◽  
Eutectic Silicon ◽  
Solution Treatment ◽  
Analytical Techniques ◽  
Intermetallic Phases ◽  
Holding Time ◽  
Age Hardening ◽  
Image Analyzer

PurposeThe influence of age-hardening solution treatment at temperature 515_C with holding time 4 hours, water quenching at 40_C and artificial aging by different temperature 130_C, 150_C, 170_C and 210_C with different holding time 2, 4, 8, 16 and 32 hours on changes in morphology of Fe-rich Al15(FeMn)3Si2 and Cu-rich (Al2Cu, Al-Al2Cu-Si) intermetallic phases in recycled AlSi9Cu3 cast alloy. Material/Methods: Recycled (secondary) AlSi9Cu3 cast alloy is used especially in automotive industry (dynamic exposed cast, engine parts, cylinder heads, pistons and so on). Microstructure was observed using a combination of different analytical techniques (scanning electron microscopy upon standard and deep etching and energy dispersive X-ray analysis - EDX) which have been used for the identification of the various phases. Quantitative study of changes in morphology of phases was carried out using Image Analyzer software NIS-Elements. The mechanical properties (Brinell hardness and tensile strength) were measured in line with STN EN ISO. Results/Conclusion: Age-hardening led to changes in microstructure include the spheroidization of eutectic silicon, gradual disintegration, shortening and thinning of Fe-rich intermetallic phases and Al-Al2Cu-Si phases were fragmented, dissolved and redistributed within _-matrix. These changes led to increase in the hardness and tensile strength in the alloy.

scholarly journals Study of the precipitation hardening process in recycled Al-Si-Cu cast alloys

2017 ◽  
Vol 62 (1) ◽  
pp. 397-403 ◽  
Author(s):  
L. Kuchariková ◽  
E. Tillová ◽  
M. Matvija ◽  
J. Belan ◽  
M. Chalupová
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Precipitation Hardening ◽  
Cast Alloy ◽  
Solution Treatment ◽  
Second Phase ◽  
Thin Foils ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Cast Alloys

AbstractThe formation of extremely small uniformly dispersed particles of a second phase within the original phase matrix during heat treatment changed material properties. Therefore the characterization of precipitation had been investigated using high resolution transmission electron microscopy (TEM) and electron diffraction of thin foils for an AlSi9Cu3 cast alloy. For investigation the hardening effect onto mechanical properties of aluminium cast was used heat treatment, which consisted from solution treatment at 515°C / 4 hours (h), followed by quenching into water with temperature 50°C and artificial aging using different temperatures 170°C and 190°C with different holding time 2, 4, 8, 16, and 32 hours. The observations of microstructure and substructure reveals that precipitation hardening has caused great changes in size, morphology and distributions of structural components, the formation of precipitates of Cu phases, and the change of mechanical properties as well.

The Microstructure and Mechanical Properties of Mg-8Zn-8Al-4RE Magnesium Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 187-190 ◽  
Author(s):  
Jun Wang ◽  
Jian Li Wang ◽  
Wen Long Xiao ◽  
Yao Ming Wu ◽  
Li Min Wang
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Grain Boundary ◽  
Cast Alloy ◽  
Testing Machine ◽  
Solution Treatment ◽  
Solid Solution Alloy ◽  
Aged Alloy ◽  
Microstructure And Mechanical Properties ◽  
Energy Spectrometer

The Mg-8Zn-8Al-4RE (RE = mischmetal, mass%) magnesium alloy was prepared by using casting method. The microstructure and mechanical properties of as-cast alloy, solid solution alloy and aged alloy samples have been investigated. Optical microscopy, X-ray diffractometery and scanning electron microscope attached energy spectrometer were used to characterize the microstructure and phase composition for the alloy. Net shaped τ-Mg32(Al,Zn)49 phase was obtained at the grain boundary, and needle-like or blocky Al11RE3 phase disperses in grain boundary and α-Mg matrix. The τ-Mg32(Al,Zn)49 phase disappeared during solution treatment and a new phase of Al2CeZn2 formed during subsequent age treatment. The mechanical properties were performed by universal testing machine at room temperature, 150 °C and 200 °C, separately. The ultimate tensile strength of as-cast alloy is lower compared to an age treatment alloy at 200 °C for 12h. The strengths decreased with enhancing test temperature, but elongation has not been effect by age treatment.

Processing of Al-Cu-Mg Alloy (V65 Grade) Bars as Feedstock for Wire Drawing

2012 ◽  
Vol 710 ◽  
pp. 167-173 ◽  
Author(s):  
Niraj Nayan ◽  
S.V.S. Narayana Murty ◽  
Abhay Kumar Jha ◽  
S.C. Sharma ◽  
K. Sreekumar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solution Treatment ◽  
Natural Aging ◽  
Wire Drawing ◽  
Direct Chill ◽  
High Plasticity ◽  
Aging Response ◽  
Different Temperatures ◽  
Aging Kinetics ◽  
Kinetics Of

Al-Cu-Mg (Russian grade V65) alloys are used for riveting applications in aerospace industries due to relatively high shear strength of the order of 25 kg/mm2 combined with a high plasticity. The main advantage of using V65 aluminum alloy for rivet application comes from its significantly slower natural aging response, which gives flexibility to carryout riveting operation even after 4 days after solution heat treatment and natural aging at room temperature. This very valuable feature is not found in its counterpart alloy AA2024 where due to rapid aging kinetics of this alloy, the riveting operation must be completed within 30 min of the solution treatment, which is many times impractical. This paper presents the processing of V65 aluminium alloy by Direct Chill (DC) casting followed by subsequent secondary processing through extrusion and forging to realize feedstock for caliber rolling. These ingots were caliber rolled to 12 mm diameter rods at different temperatures and mechanical properties were evaluated in T6 and T4 tempers. Detailed microstructural examination using optical microscopy and fractography of the tensile tested samples using scanning electron microscopy were carriedout to correlate microstructure and mechanical properties.

Microstructure and Property of Rapid-Solidified Al-Si Alloys by Solution Treatment

2010 ◽  
Vol 139-141 ◽  
pp. 243-246
Author(s):  
Ai Qin Wang ◽  
Jing Pei Xie ◽  
Wen Yan Wang ◽  
Ji Wen Li ◽  
Luo Li Li
Keyword(s):  
Melt Spinning ◽  
Silicon Particle ◽  
Eutectic Silicon ◽  
Solution Process ◽  
Solution Treatment ◽  
Natural Aging ◽  
Primary Silicon ◽  
Heating Time ◽  
Supersaturated Solution ◽  
The Matrix

A rapid-solidified hypereutectic Al-21Si-0.8Mg-1.5Cu-0.5Mn alloys strips has been prepared by single roller melt-spinning. The effects of solution technology on the microstructures and properties of the strips have been investigated by SEM, TEM. The results showed that the nucleation and growth of primary silicon are suppressed and α-Al is nucleated which prior to eutectic. The Cu, Mg and Mn are all supersaturated solution in α-Al. The major part of Si solution in α-Al, and the rest are precipitated by the micro-nanocrystals eutectic silicon. The metastable microstructures of micro-nanocrystals hypoeutectic are formed. And in the solution process, Si are precipitated from the matrix and gradually aggregate up to form small particles distributing in the matrix with the heating time. At 480°C for 100 minutes followed by quenching in water and a natural aging for 96h, the finer and more roundness of silicon particle and the maximum Vickers hardness are formed.

Effect of Heat Treatment on the Microstructure of Gravity Cast and Squeeze Cast Al-Si-Mg Alloy

2015 ◽  
Vol 830-831 ◽  
pp. 164-167
Author(s):  
Arjun Bala Krishnan ◽  
Kavin Selvaraj ◽  
Akhil Madhusoodhanan Geethakumari ◽  
Ravi Manickam
Keyword(s):  
Heat Treatment ◽  
Squeeze Casting ◽  
Cast Alloy ◽  
Eutectic Silicon ◽  
Solution Treatment ◽  
A356 Alloy ◽  
Sand Cast ◽  
Squeeze Cast ◽  
Cast Alloys ◽  
Gravity Cast

The present work deals with the effect of solutionising heat treatment on the features of Al-7Si-0.3Mg (A356) alloy in terms of microstructural modifications and hardness. The microstructure of sand cast and gravity cast alloys are coarse which results in lower strength compared to the alloys cast using modern casting techniques such as squeeze casting which is used for the fabrication of near-net-shaped castings. The influence of enhanced cooling rate on the hardness and microstructure of the squeeze casting technique has been exploited in the present study. In order to optimise the heat treatment process, the microstructure of the gravity and squeeze cast alloys were compared after solution treatment. The quantitative analysis of the microstructure was carried out using an image analyser attached to the optical microscope. The aspect ratio, particle count and circularity of eutectic silicon and SDAS are measured. The squeeze cast alloy is found to have finer microstructure with enhanced properties compared to the gravity cast alloy.

Fatigue Strength of Ion Nitrided Tool Steel

2006 ◽  
Vol 324-325 ◽  
pp. 475-478
Author(s):  
Mian Zhang ◽  
Shinichi Nishida ◽  
Nobusuke Hattori
Keyword(s):  
Fatigue Strength ◽  
Fatigue Test ◽  
Tool Steel ◽  
Surface Composition ◽  
Fatigue Testing ◽  
Testing Machine ◽  
Surface Hardness ◽  
Fatigue Properties ◽  
Ion Nitriding ◽  
Rotating Bending Fatigue

The authors have studied and clarified that ion nitriding was able to improve the fatigue properties of tool steel. Five kinds of ion nitriding methods (ion nitriding condition is different) were used in this study. The fatigue test had been performed using a rotating bending fatigue testing machine to investigate the effects of ion nitriding on fatigue properties of tool steel. The fractography was analyzed using a scanning electron microscope (SEM), and hardness distribution was also investigated using a microhardness tester. As a result, the fatigue strength and hardness of the ion nitrided specimen increased after ion nitriding processing. It is considered that the compressive residual stress which produced by ion nitriding processing in the layer reduced fatigue fracture, and the altered surface composition improved surface hardness. According to the results of the fatigue test, the optimal ion nitriding method on improving the fatigue limit of tool steel was determined. The hardness of the specimens remarkably increased after ion nitriding processing.

scholarly journals Investigation of the Effect of Heat Treatment on the Microstructures and Mechanical Properties of Al-13Si-5Cu-2Ni Alloy

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 688
Author(s):  
Zhi-Fa Wang ◽  
Tian-Jing Miao ◽  
Shu-Qing Kou ◽  
Shuang Zhang ◽  
Feng Qiu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
Cast Alloy ◽  
Eutectic Silicon ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Solution Treatment Temperature ◽  
Solid Solution Treatment ◽  
Microstructures And Mechanical Properties

An experimental investigation was carried out to study the effects of solid solution treatment and aging treatment on the microstructures and mechanical properties of an Al-13Si-5Cu-2Ni alloy. The results show that the size of eutectic silicon decreased with solid solution treatment temperature increasing until 510 °C. Subsequently, the eutectic silicon size continued to increase as the temperature increased to 520 °C. Initially, the acicular eutectic silicon of the as-cast alloy was 10.1 μm in size. After the solid solution treatment at 510 °C, the eutectic silicon size was reduced to 6.5 μm. The θ′ phase is the main strengthening phase in the alloy, therefore, the effect of aging treatment on θ′ phases was explored. As the aging time increased, the diameter, length, and fraction volume of the θ′ phases were found to increase. The main reason for the improved performance of this alloy following heat treatment is the passivation spheroidization of the silicon phase and Orowan strengthening due to the θ′ phases. The optimal tensile strength of an Al-13Si-5Cu-2Ni alloy was obtained after solid solution treatment at 510 °C for 8 h followed by an aging treatment at 165 °C for 8 h. Therefore, this work has great significance for promoting the application of Al alloys at high temperatures.

Effect of Pressure on Structure and Properties of Lost Foam Casting of Al-11Si Cast Alloy

2011 ◽  
Vol 110-116 ◽  
pp. 639-643 ◽  
Author(s):  
Ali Asghar Niakan ◽  
M.H. Idris ◽  
Majid Karimian ◽  
A. Ourdjini
Keyword(s):  
Cast Alloy ◽  
Eutectic Silicon ◽  
Testing Machine ◽  
Applied Pressure ◽  
Casting Process ◽  
Optical Microscope ◽  
Lost Foam Casting ◽  
Image Analyzer ◽  
Effect Of Pressure ◽  
Lost Foam

The paper presents the results of an investigation on aluminum-silicon (LM6) alloy using pressurized lost foam casting process. The study investigated the effect of pressure on casting integrity-geometry, eutectic silicon spacing, particle roundness and hardness. Following air pressures: 1bar, 2bar, 3bar and 4bar were applied on the solidifying alloy. The eutectic silicon spacing and particle roundness were measured using optical microscope which was equipped with image analyzer by averaging of at least ten results as well as Vickers hardness testing machine. For casting integrity-geometry all surfaces of solidified castings were captured by digital camera for better observation. The results show that applying pressure during solidification of the LM6 alloy has significant influence on casting integrity-geometry, eutectic silicon spacing, particle roundness and hardness of the alloy. By increasing the applied pressure, solidification time decline. Consequently, silicon spacing reduces as well as increasing of hardness. Besides, rising air pressure lead to fulfilling of molten which improves the casting integrity and particle roundness.

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