scholarly journals Microstructural Evolution as a Function of Increasing Aluminum Content in Novel Lightweight Cast Irons

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1646
Author(s):  
Alejandro Obregon ◽  
Jon Mikel Sanchez ◽  
David Eguizabal ◽  
Jose Carlos Garcia ◽  
Gurutze Arruebarrena ◽  
...  
Keyword(s):  
Microstructural Evolution ◽  
Aluminum Content ◽  
Induction Furnace ◽  
Indentation Test ◽  
Microstructural Characterization ◽  
Casting Process ◽  
Great Decrease ◽  
Cast Irons ◽  
Gravity Casting ◽  
Al Content

In the context of the development of new lightweight materials, Al-alloyed cast irons have a great potential for reducing the weight of the different part of the vehicles in the transport industry. The correlation of the amount of Al and its effect in the microstructure of cast irons is not completely well established as it is affected by many factors such as chemical composition, cooling rate, etc. In this work, four novel lightweight cast irons were developed with different amounts of Al (from 0 wt. % to 15 wt. %). The alloys were manufactured by an easily scalable and affordable gravity casting process in an induction furnace, and casted in a resin-bonded sand mold. The microstructural evolution as a function of increasing Al content by different microstructural characterization techniques was studied. The hardness of the cast irons was measured by the Vickers indentation test and correlated with the previously characterized microstructures. In general, the microstructural evolution shows that the perlite content decrease with the increment of wt. % of Al. The opposite occurs with the ferrite content. In the case of graphite, a slight increment occurs with 2 wt. % of Al, but a great decrease occurs until 15 wt. % of Al. The addition of Al promotes the stabilization of ferrite in the studied alloys. The hardness obtained varied from 235 HV and 363 HV in function of the Al content. The addition of Al increases the hardness of the studied cast irons, but not gradually. The alloy with the highest hardness is the alloy containing 7 wt. % Al, which is correlated with the formation of kappa-carbides and finer perlite.

Effect of Al on microstructure and mechanical properties of as-cast Mg-8Gd-4Y-1Zn alloy

2020 ◽  
Vol 67 (1) ◽  
pp. 101-105
Author(s):  
Yongxin Zhou ◽  
Qian Li ◽  
Zhiguo Xing ◽  
Renze Zhou ◽  
Zhenhua Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Material Characterization ◽  
Aluminum Content ◽  
Gravity Casting ◽  
Content Type ◽  
Al Content ◽  
Casting Technology ◽  
Microstructure And Mechanical Properties ◽  
Lpso Structure

Purpose This paper aims to investigate the effect of aluminum addition on the microstructure and mechanical properties of Mg-8Gd-4Y-1Zn alloy. Design/methodology/approach Mg-8Gd-4Y-1Zn-xAl (x = 0, 0.5, 1.0, 1.5, 2.0 Wt.%) alloys were prepared by the conventional gravity casting technology, and then microstructures, phase composition and mechanical properties were investigated by material characterization method, systematically. Findings Results show that the as-cast microstructure of Mg-8Gd-4Y-1Zn alloy mainly consists of a-Mg matrix as well as Mg12REZn (18 R LPSO structure), and island-like Mg3(RE, Zn) phase is distributed at the grain boundary. The addition of a small amount of Al (0.5 Wt.%) can decrease the content of island-like Mg3(RE, Zn) phase, but significantly increase the content of long-period stacking ordered (LPSO) structure, resulting in the improvement of both tensile strength and elongation of Mg-8Gd-4Y-1Zn alloy. However, the addition of excessive Al will consume Re element and decrease the amount of LPSO structure, leading to the decrease of tensile properties. When the content of Al is 0.5 Wt.%, the tensile strength and elongation are 225 MPa and 9.0% of Mg-8Gd-4Y-1Zn alloy, which are 14% and 29% higher than that of Mg-8Gd-4Y-1Zn alloy, respectively. Originality/value Adding aluminum to Mg-8Gd-4Y-1Zn alloy strengthens its mechanical properties. And the effect of Al content on the alloy strengthening. The formation mechanism of LPSO structure with different aluminum content was revealed.

Study on TiCp/Al Master Alloy in Magnesium Matrix Composites

2010 ◽  
Vol 97-101 ◽  
pp. 1726-1729
Author(s):  
Xin Ying Teng ◽  
Deng Wei Zhang ◽  
Bo Li
Keyword(s):  
Master Alloy ◽  
Aluminum Content ◽  
Sintering Temperature ◽  
Matrix Material ◽  
Microstructural Characterization ◽  
Magnesium Matrix Composites ◽  
Al Content ◽  
Average Grain Size ◽  
The Matrix ◽  
Tic Particulates

Effects of aluminum content and sintering temperature on microstructures of TiCp/Al master alloy were investigated. The DSC results showed that reaction temperatures of the Al-Ti-C system were influenced by aluminum content. The average grain size of TiCp in the master alloy was 0.5～1μm with 40wt% Al content at 750°C sintering temperature. TiCp/AZ91 composites were fabricated through remelting TiCp/Al master alloy in magnesium alloy. Microstructural characterization of the TiCp/AZ91 composites showed relatively uniform distribution of TiC particulates in the matrix material and the hardness of the composites was improved significantly.

The Effects of Two-Step Solution Heat Treatment of Al-6Si-2Cu Alloy for Lightweight Automotive on Mechanical Properties

2015 ◽  
Vol 1110 ◽  
pp. 158-162
Author(s):  
Seung Pyo Hong ◽  
Chung Seok Kim
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Inductively Coupled Plasma ◽  
Solution Heat Treatment ◽  
Microstructural Characterization ◽  
Casting Process ◽  
Optical Microscope ◽  
Intermetallic Phases ◽  
Single Step ◽  
Gravity Casting

The effects of two-step solution heat treatment of aluminum alloy for lightweight automotive have been investigated. The test specimens, Al-6Si-2Cu alloys are prepared by gravity casting process. Solution heat treatments in this study are applied to improve of mechanical properties through a single-step or two-step solution heat treatment. For the microstructural characterization, inductively coupled plasma mass spectromerty (ICP-MS), optical microscope (OM) and scanning electron microscope (SEM) analyses are conducted in specimen. The X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) analyses are also applied to identify the intermetallic phases with quantitative and qualitative analyses. Micro Vickers hardness and static tensile test are achieved. The microstructure of gravity casting specimen represents a typical dendrite structure having a secondary dendrite arm spacing (SDAS) of 37um. In addition to the Al matrix, a large amount of coarsen eutectic Si, Al2Cu intermetallic phases and Fe-rich phases are identified. After solution heat treatment, the mechanical properties of two-step solution heat treatment alloy show higher values than as-cast and single-step solution specimens. Consequentially, the two-step solution heat treatment could be used in automotive parts to improve mechanical properties.

scholarly journals The Influence of Aluminum Content on Oxidation Resistance of New-Generation ODS Alloy at 1200 °C

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1478 ◽  
Author(s):  
Luděk Stratil ◽  
Vít Horník ◽  
Petr Dymáček ◽  
Pavla Roupcová ◽  
Jiří Svoboda
Keyword(s):  
Oxidation Resistance ◽  
Cross Sections ◽  
Aluminum Content ◽  
Energy Dispersive Spectrometer ◽  
Oxide Dispersion Strengthened ◽  
Xrd Analysis ◽  
Al Content ◽  
Α Al2o3 ◽  
New Generation ◽  
Ods Alloy

The aim of the paper is to evaluate the effect of aluminum content on the oxidation resistance of new-generation of oxide dispersion strengthened (ODS) alloy at 1200 °C. Three grades of the alloy of chemical composition Fe-15Cr-xAl-4Y2O3 with different Al contents x = 0.3 wt.%, 2.0 wt.% and 5.5 wt.% are prepared by mechanical alloying. The alloys are consolidated by high temperature rolling followed by heat treatment. To study the oxidation resistance the samples are isothermally aged in the air for 1 h, 4 h, 16 h and 64 h at 1200 °C. The oxidation kinetics, composition and formation mechanism of the oxide layers are analyzed. The weight gain of prepared steels is estimated. The kinetics of oxidation is studied on metallographic cross-sections of the exposed samples by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) analysis. The oxides on the surfaces are identified by X‑ray diffraction (XRD) analysis. The Al content significantly enhances the oxidation resistance of the alloy. For a sufficiently high Al content in the alloy a compact oxide layer of α‑Al2O3 on the surface is formed, which significantly suppresses further oxidation process.

scholarly journals Composite Material of PDMS with Interchangeable Transmittance: Study of Optical, Mechanical Properties and Wettability

2021 ◽  
Vol 5 (4) ◽  
pp. 110
Author(s):  
Flaminio Sales ◽  
Andrews Souza ◽  
Ronaldo Ariati ◽  
Verônica Noronha ◽  
Elder Giovanetti ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Room Temperature ◽  
Casting Process ◽  
Optical Characteristics ◽  
Smart Devices ◽  
Superhydrophobic Coating ◽  
Gravity Casting ◽  
High Flexibility ◽  
Physical And Chemical

Polydimethylsiloxane (PDMS) is a polymer that has attracted the attention of researchers due to its unique properties such as transparency, biocompatibility, high flexibility, and physical and chemical stability. In addition, PDMS modification and combination with other materials can expand its range of applications. For instance, the ability to perform superhydrophobic coating allows for the manufacture of lenses. However, many of these processes are complex and expensive. One of the most promising modifications, which consists of the development of an interchangeable coating, capable of changing its optical characteristics according to some stimuli, has been underexplored. Thus, we report an experimental study of the mechanical and optical properties and wettability of pure PDMS and of two PDMS composites with the addition of 1% paraffin or beeswax using a gravity casting process. The composites’ tensile strength and hardness were lower when compared with pure PDMS. However, the contact angle was increased, reaching the highest values when using the paraffin additive. Additionally, these composites have shown interesting results for the spectrophotometry tests, i.e., the material changed its optical characteristics when heated, going from opaque at room temperature to transparent, with transmittance around 75%, at 70 °C. As a result, these materials have great potential for use in smart devices, such as sensors, due to its ability to change its transparency at high temperatures.

scholarly journals Silicon reduces aluminum content in tissues and ameliorates its toxic effects on potato plant growth

2016 ◽  
Vol 46 (3) ◽  
pp. 506-512 ◽  
Author(s):  
Athos Odin Severo Dorneles ◽  
Aline Soares Pereira ◽  
Liana Verônica Rossato ◽  
Gessieli Possebom ◽  
Victória Martini Sasso ◽  
...  
Keyword(s):  
Chemical Element ◽  
Shoot Growth ◽  
Aluminum Content ◽  
Solanum Tuberosum L ◽  
Toxic Effects ◽  
Al Content ◽  
Potato Plants ◽  
High Affinity ◽  
Root And Shoot Growth ◽  
Tolerant Genotype

ABSTRACT: Aluminum (Al) is highly toxic to plants, causing stress and inhibiting growth and silicon (Si) is considered beneficial for plants. This chemical element has a high affinity with Al. The aim of this study was to investigate the potential of Si to mitigate the toxic effects of Al on potato ( Solanum tuberosum L.) plants and assess whether this behavior is different among genotypes with differing degrees of sensitivity to Al. Potato plants of the genotypes SMIJ319-7 (Al-sensitive) and SMIF212-3 (Al-tolerant) were grown for fourteen days in nutrient solution (without P and pH 4.5±0.1) under exposure to combinations of Al (0 and 1.85mM) and Si (0, 0.5 and 1.0mM). After this period, shoot and roots of the two genotypes were collected to determine Al content in tissues and assess morphological parameters of root and shoot growth. Roots of both genotypes accumulated more Al than shoots and the Al-tolerant genotype accumulated more Al than the sensitive one, both in roots and in shoot. Furthermore, the presence of 0.5 and 1.0mM Si together with Al reduced the Al content in shoot in both genotypes and in roots of the Al-tolerant genotype, respectively. Si ameliorated the toxic effects of Al with regard to number of root branches and leaf number in both potato genotypes. Si has the potential to mitigate the toxic effects of Al in potato plants regardless of Al sensitivity.

Microstructure and Hardness of Gray Cast Iron as a Product of Solidification in Permanent Mold

2020 ◽  
Vol 991 ◽  
pp. 37-43
Author(s):  
Agus Yulianto ◽  
Rudy Soenoko ◽  
Wahyono Suprapto ◽  
As’ad Sonief ◽  
Agung Setyo Darmawan ◽  
...  
Keyword(s):  
Cast Iron ◽  
Cooling Rate ◽  
Induction Furnace ◽  
Gray Cast Iron ◽  
Casting Process ◽  
Melting Process ◽  
Gray Cast ◽  
Outer Side ◽  
Permanent Mold ◽  
Test Results

Molds of metal are widely used in the casting process. The cooling rate in solidification of castings product with metal molds on the outer side and inner side is different. Therefore, sizes and types of phase will be also different. This study aims to investigate the microstructure andhardness of gray cast iron. To realize this research, the gray cast iron melting process was carried out in an induction furnace. Melted gray cast iron was poured into a Ferro Casting Ductile mold that has been through a preheating process at a temperature of 300 o C. The gray cast iron is then tested for composition, microstructure and hardness. The test results show that the part containing morecementite phase will be harder.

scholarly journals Corrosion investigations of Al-Si casting alloys in 0.6 M NaCl solution

2021 ◽  
Vol 41 (3) ◽  
Author(s):  
Sunčana Smokvina Hanza ◽  
Ladislav Vrsalović ◽  
Lovro Štic ◽  
Lovro Liverić
Keyword(s):  
Potentiodynamic Polarization ◽  
Electrochemical Behavior ◽  
Die Casting ◽  
Electrochemical Corrosion ◽  
Microstructural Characterization ◽  
Casting Process ◽  
Corrosion Current ◽  
Optical Microscope ◽  
Open Circuit ◽  
Polarization Measurements

This paper presents results of the corrosion investigations of specimens made from finished parts for the automotive industry, produced by high-pressure die casting and gravity die casting process of six Al-Si alloys (40000 series). Open circuit potential and potentiodynamic polarization measurements have been performed using a potentiostat with three-electrode set-up in 0.6 M NaCl naturally aerated solution. Microstructural characterization before and after electrochemical investigations has been carried out with optical microscope to establish the connection between microstructure and corrosion parameters of investigated alloys and to analyze and record surface changes of each sample due to electrochemical corrosion. All alloys show good corrosion resistance, which manifests with low values of corrosion rates, calculated from the corrosion current densities obtained from potentiodynamic polarization measurements. Differences in electrochemical behavior appear due to the distinctions in their chemical composition and microstructure. The type of casting process does not affect electrochemical behavior of Al-Si alloys.

scholarly journals Microstructural Characterization Of Laser Heat Treated AISI 4140 Steel With Improved Fatigue Behavior

2015 ◽  
Vol 60 (2) ◽  
pp. 1331-1334 ◽  
Author(s):  
M.C. Oh ◽  
H. Yeom ◽  
Y. Jeon ◽  
B. Ahn
Keyword(s):  
Fatigue Strength ◽  
Alloy Steel ◽  
Microstructural Evolution ◽  
Fatigue Behavior ◽  
Microstructural Characterization ◽  
Optical Microscope ◽  
Heat Treated ◽  
Aisi 4140 ◽  
Ultrasonic Fatigue

Abstract The influence of surface heat treatment using laser radiation on the fatigue strength and corresponding microstructural evolution of AISI 4140 alloy steel was investigated in this research. The AISI 4140 alloy steel was radiated by a diode laser to give surface temperatures in the range between 600 and 800°C, and subsequently underwent vibration peening. The fatigue behavior of surface-treated specimens was examined using a giga-cycle ultrasonic fatigue test, and it was compared with that of non-treated and only-peened specimens. Fatigue fractured surfaces and microstructural evolution with respect to the laser treatment temperatures were investigated using an optical microscope. Hardness distribution was measured using Vickers micro-hardness. Higher laser temperature resulted in higher fatigue strength, attributed to the phase transformation.

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