The Influence of Yttrium Rich Intermetallic Phases and Heat Treatment on the Microstructure, Hardness and Wear Properties of Al-15%Mg2Si Composite

2011 ◽  
Vol 471-472 ◽  
pp. 1165-1170 ◽  
Author(s):  
H.R. Jafari Nodooshan ◽  
M. Emamy ◽  
N. Nemati ◽  
A. Bahrami
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Wear Behavior ◽  
Hardness Measurement ◽  
Intermetallic Phases ◽  
Track Length ◽  
Dry Sliding Wear ◽  
Wear Properties ◽  
Wear Rates ◽  
Before And After

This study was undertaken to investigate the effect of different concentrations of Yttrium (0.1, 0.3, 0.5, 1.0 wt.%) and heat treatment on the microstructure, hardness and wear resistance of an in-situ cast composite (Al-15%Mg2Si ). The microstructural study of the composite before and after solution and ageing showed both primary and secondary Mg2Si phases in all specimens and intermetallics containing Y (Al2Y) were visible after Solution at 520 °C for 4 hours. Hardness measurement demonstrates that the addition of Y increases the hardness gradually but a reduction in the hardness of heat treated specimen’s occurs with the addition of Y ( 0.5%Y).Wear tests were performed using a pin on disk apparatus. The MMCs were rubbed against a carbon steel pin under a load of 10 and 20 N at a sliding velocity of 0.1 ms−1; track length of 1500 m. The degree of improvement in dry sliding wear resistance brought about by Y addition is strongly dependent on the formation of Yttrium rich intermetallic phases as well as heat treatment influence and the wear behavior determined through the precise measurement of weight loss of the samples and wear rates. Worn surfaces were analyzed by scanning electron microscopy (SEM).

Process optimization using grey relational analysis in dry sliding wear behavior on SiC/B4C/Talc reinforced Al 6061 hybrid metal matrix composite

2021 ◽  
Vol 118 (6) ◽  
pp. 614
Author(s):  
Chellamuthu Ramesh Kumar ◽  
Subramanian Baskar ◽  
Ganesan Ramesh ◽  
Pathinettampadian Gurusamy ◽  
Thirupathy Maridurai
Keyword(s):  
Wear Resistance ◽  
Metal Matrix ◽  
Wear Behavior ◽  
Base Alloy ◽  
Specific Weight ◽  
Dry Sliding Wear ◽  
Wear Properties ◽  
Weight Percentage ◽  
Casting Technique ◽  
Grey Relational

In this research, investigations were carried out on Al6061 base alloy with the changing weight percentage of silicon carbide (SiC) and boron carbide (B4C) with keeping the amount of talc constant. The main objective of this present study was to improve the wear resistance of aluminum alloy using SiC/B4C/talc ceramic particles using stir-casting technique and how the eco-friendly talc content influencing the solid lubricity during the abrasion process. The experiments were conducted via orthogonal array of L27 using Taguchi’s method. The optimum value along with the coefficient of friction was obtained on the basis of grey relational equations and ANOVA, which helped in analysis of most influential input parameters such as applied load, sliding speed, sliding distance and percentage of reinforcement. Conformation tests were performed for the purpose of validation of the experimental results. The specimens were analyzed using scanning electron microscope (SEM) with EDX for micro structural studies. The SiC, B4C and talc presence in the composite helped to improve the mechanical properties, according to the results. The presence of solid lubricant talc as reinforcement to the aluminum hybrid composite reduced the wear properties and decreased the co-efficient friction. These wear resistance improved aluminum metal matrix composites could be used in automobile, defense and domestic applications where high strength and wear resistance required with lesser specific weight.

scholarly journals Effect of Necklace-Type Distribution of SiC Particles on Dry Sliding Wear Behavior of As-Cast AZ91D/SiCp Composites

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 296 ◽  
Author(s):  
Chao Sun ◽  
Nannan Lu ◽  
Huan Liu ◽  
Xiaojun Wang ◽  
Xiaoshi Hu ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Sliding Wear ◽  
Wear Behavior ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Interface Bonding ◽  
Type Distribution ◽  
Wear Rates ◽  
Sic Particles ◽  
The Matrix

In this study, the dry sliding wear behaviors of SiC particle reinforced AZ91D matrix composites fabricated by stirring casting method were systematically investigated. The SiC particles in as-cast composites exhibited typical necklace-type distribution, which caused the weak interface bonding between SiC particles and matrix in particle-segregated zones. During dry sliding at higher applied loads, SiC particles were easy to debond from the matrix, which accelerated the wear rates of the composites. While at the lower load of 10 N, the presence of SiC particles improved the wear resistance. Moreover, the necklace-type distribution became more evident with the decrease of particle sizes and the increase of SiC volume fractions. Larger particles had better interface bonding with the matrix, which could delay the transition of wear mechanism from oxidation to delamination. Therefore, composites reinforced by larger SiC particles exhibited higher wear resistance. Similarly, owing to more weak interfaces in the composites with high content of SiC particles, more severe delamination occurred and the wear resistance of the composites was impaired.

Microstructure and Wear Properties of In Situ Production of (Fe,Cr)7C3 Particulate Bundles Reinforced Iron Matrix Composites

2013 ◽  
Vol 652-654 ◽  
pp. 64-68 ◽  
Author(s):  
Jing Lai Tian ◽  
Fang Xia Ye ◽  
Li Sheng Zhong ◽  
Yun Hua Xu
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Treatment Time ◽  
Heat Treatment Time ◽  
Wear Testing ◽  
Dry Sliding Wear ◽  
Matrix Composites ◽  
Wear Properties ◽  
Iron Matrix

In-situ production of (Fe,Cr)7C3 particulate bundles-reinforced iron matrix composites were prepared by infiltration casting between Cr wires and white cast iron at 1200°C plus subsequent heat treatment. The composites prepared under different heat treatment time were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), macrohardness test and pin-on-disc wear resistance test. The results show that the composite is mainly consist of (Fe,Cr)7C3 carbides and γ-Fe. The area of the particulate bundles gradually increases with the increase of heat treatment time, the microstructure evolved from eutectic to hypoeutectic, and the morphologies of the reinforcements present chrysanthemum-shaped, granular and intercrystalline eutectics, respectively. The (Fe,Cr)7C3 particulate bundles reinforced composite has high macrohardness and excellent wear resistance under dry sliding wear testing conditons.

Wear Resistance Improvement by Nanostructured Surface Layer Produced by Burnishing

2018 ◽  
Vol 917 ◽  
pp. 231-235 ◽  
Author(s):  
Hirotaka Kato ◽  
Hiroto Ueki ◽  
Keitaro Yamamoto ◽  
Kazufumi Yasunaga
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Carbon Steel ◽  
Rotating Disk ◽  
Dry Sliding Wear ◽  
Wear Properties ◽  
Surface Layers ◽  
Wear Rates ◽  
Strain And Strain Rate ◽  
Burnishing Process

Burnishing, which is one of the most powerful processes for microstructural evolution, was performed by a cemented carbide ball (6 mm in diameter) that was loaded and fed on the flat surface of a rotating disk specimen of carbon steel using a lathe machine. The effects of burnishing process parameters such as force and rotation speed on the surface roughness, microstructure and hardness were investigated. In addition the dry sliding wear properties of the burnished surface layers were studied using a ball-on-disk friction method. It was found that the burnished surface was much smoother than as-turned surface (before burnishing) owing to the plastic flow of the surface asperities through the rubbing motion of the burnishing ball. Nanostructure in the 30 - 50 nm grain size range was formed in the burnished sub-surface layer, and the hardness significantly increased due to the grain refinement. The nanocrystalline microstructure was observed at high burnishing forces and speeds owing to the high strain and strain rate of the friction-induced plastic deformation. Moreover the burnishing process reduced the specific wear rates by a factor of six. Thus we concluded that the wear resistance of carbon steel can be significantly improved by burnishing due to the smooth surface and nanostructured sub-surface layers.

EFFECT OF THIXOFORMING ON THE WEAR PROPERTIES OF AL-SI-CU ALUMINUM ALLOY

2017 ◽  
Vol 79 (5-2) ◽  
Author(s):  
Khaled Salem Alhawari ◽  
Mohd Zaidi Omar ◽  
Mariyam Jameelah Ghazali ◽  
Mohd Shukor Salleh ◽  
Mohammed Naser Abdulrazaq
Keyword(s):  
Wear Behavior ◽  
Cast Alloy ◽  
Liquid Fraction ◽  
Casting Process ◽  
Primary Phase ◽  
Wear Behaviour ◽  
Dry Sliding Wear ◽  
Wear Properties ◽  
Dendritic Microstructure ◽  
Wear Rates

In this study a hypoeutectic Al-6Si-3Cu aluminium alloy was synthesized using two different routes: the thixoforming process and the conventional mould casting process. The microstructural features, hardness and wear behavior of thixoformed alloy have been evaluated and compared with that of as-cast alloy. Cooling slope method was used to produce the non-dendritic microstructure feedstock for thixoforming. Thixoforming was carried out at 50% liquid fraction. The dry sliding wear behaviour of the produced alloys was investigated under two loads; namely, 10 and 50 N and 1m/s sliding speed for 9 km sliding distance. The thixoformed alloy exhibited globular primary phase morphology with fine and uniform distributed Si and intermetallic particles. On the contrary, dendritic primary phase, coarse flaky silicon particles and segregated microstructure has been observed in conventional cast alloy. Thixoformed alloy exhibited improvement in the wear resistance in comparison to the conventional cast alloy, which may be attributed to the microstructural enhancement resulting in improved hardness. The thixoformed samples displayed lower volume loss of ~16.20 mm3 and ~42.40 mm3 at loads of 10 and 50 N respectively compared with that of conventional cast samples. On the basis of observations and analyses on the wear rates and worn surfaces, the wear mechanism of the alloys was dominantly controlled by abrasive, adhesive and minor delamination.

scholarly journals Microstructure and Wear Resistance of Mg2Si–Al Composites Fabricated Using Semi-Solid Extrusion

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 596 ◽  
Author(s):  
Xiaobo Liu ◽  
Miao Yang ◽  
Dekun Zhou ◽  
Yuguang Zhao
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Dry Sliding Wear ◽  
Isothermal Heat Treatment ◽  
Wear Properties ◽  
Gravity Casting ◽  
Al Composite ◽  
The Matrix ◽  
Semi Solid

In situ Mg2Si–Al composites were prepared by using gravity casting and semi-solid extrusion. After P modification, the primary Mg2Si transformed to polygonal blocks. Extraction tests showed that the Mg2Si crystals had octahedral and tetrakaidekahedral morphologies. The semi-solid microstructure of the double-spheroidized α-Al matrix and reinforced-phase Mg2Si was successfully obtained by using semi-solid extrusion. Extraction tests showed that the Mg2Si crystals had a spherical morphology. Dry sliding wear behaviors of in situ Mg2Si–Al composites fabricated by using gravity casting and semi-solid extrusion with isothermal heat treatment holding times of 50, 60, and 160 min against 45 steel, under conditions of different sliding speeds and loads, were investigated. The worn surfaces were analyzed using SEM and EDS techniques. The results showed that Mg2Si–Al composites fabricated by using semi-solid extrusion were superior in terms of wear resistance to Mg2Si–Al composites fabricated by using gravity casting, because the former had uniformly distributed spherical reinforced phase particles of Mg2Si with weaker stress concentration around the particles, delaying the generation and expansion of cracks. The Mg2Si particles were not easily detached from the matrix, and once they fell off, the Mg2Si particles only served as spherical abrasive grains, with relatively small cutting and wear properties for the composite material. It was found that the Mg2Si/Al composite fabricated by using semi-solid extrusion with an isothermal heat treatment holding time of 60 min had the best wear resistance. The failure mechanisms of Mg2Si/Al composites were found to be mainly adhesive wear and abrasive wear.

Investigation of Wear Properties of Al-4.5wt.%Cu Nano-Composite Reinforced with Different Weight Percent of TiC Nano Particles Produced by Mechanical Alloying

2012 ◽  
Vol 545 ◽  
pp. 124-128
Author(s):  
Rasoul Azari Khosroshahi ◽  
Narguess Nemati ◽  
Masoud Emamy ◽  
Naghi Parvini ◽  
Ashkan Zolriasatein
Keyword(s):  
Wear Behavior ◽  
Microstructural Characterization ◽  
Weight Percent ◽  
High Energy ◽  
Nano Particles ◽  
Track Length ◽  
Dry Sliding Wear ◽  
Matrix Composites ◽  
Wear Properties ◽  
Pin On Disk

Resistance to wear is an important factor in design and selection of structural components in relative motion against a mating surface. The present work deals with studies on the wear behavior of metal matrix composites manufactured using powder metallurgy technique of ball milled mixing in a high energy attritor and using a blend-press-sinter methodology. Matrix of pre–mechanical alloyed Al-4.5 %wt Cu was used to which different weight percents of nano-sized TiC reinforcement were added. Microstructural characterization of the materials revealed reasonably uniform distribution of TiC reinforcement and presence of minimal porosity. Wear tests were performed using a pin on disk apparatus. The MMCs were rubbed against a carbon steel pin under loads of 10 and 20 N at a sliding velocity of 0.1 ms−1; the environmental humidity lower than 30% and a track length of 1500 m. The degree of improvement in dry sliding wear resistance and hardness brought about by reinforcement is strongly dependent on the weight percent of reinforcement and the wear behavior was determined through the precise measurement of weight loss of the samples. Worn surfaces were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).

Wear Properties of Al-17Si Alloys with Variable Fe Levels Formed by Semi-Solid Process

2014 ◽  
Vol 217-218 ◽  
pp. 111-118
Author(s):  
Shu Sen Wu ◽  
Chong Lin ◽  
Shu Lin Lü ◽  
Ping An
Keyword(s):  
Wear Resistance ◽  
Applied Load ◽  
Volume Fraction ◽  
Wear Behavior ◽  
Dry Sliding Wear ◽  
Wear Properties ◽  
Load Range ◽  
Casting Alloys ◽  
Pin On Disc ◽  
Semi Solid

The Fe-rich Al-Si alloys have the potential to be used to make wear-resistant parts. However, there has been few work devoted to study the wear behavior of the hypereutectic Al-Si alloys with about 2% Fe (mass %). In this work, the semi-solid slurry of the alloy was prepared by an ultrasonic vibration (USV) process. The effect of Fe content on dry sliding wear properties of the alloys rheo-casted after USV treatment was investigated. The wear tests were carried out using a pin-on-disc wear tester at four different loads of 50N, 100N, 150N and 200N at a constant sliding speed of 0.75m/s. The results show that the wear rate of USV treated alloy increases almost linearly as the applied load increases from 50 N to 200N. The alloys made with semi-solid process exhibited improved wear resistance at the entire applied load range in comparison to the conventional casting alloys. At the applied load of 50N, oxidative wear is the dominant mechanism for the alloys with USV treatment. At 200N, a combination of delamination and oxidation wear is the main wear mechanism. The wear resistance of Al-17Si alloys containing 2% to 3% Fe is closely related to the morphology, size and volume fraction of Fe-bearing compounds, which can be changed by USV semi-solid process.

Dry Sliding Wear of Lu2O3 Sialon Ceramics

2006 ◽  
Vol 317-318 ◽  
pp. 351-354
Author(s):  
Mark I. Jones ◽  
Kiyoshi Hirao ◽  
Hideki Hyuga ◽  
Yukihiko Yamauchi
Keyword(s):  
Wear Resistance ◽  
Composite Materials ◽  
Wear Mechanism ◽  
Wear Behaviour ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Wear Properties ◽  
Experimental Conditions ◽  
Wear Rates ◽  
Order Of Magnitude

The effects of microstructure and composition on the wear properties of Lu sialon ceramics have been studied under dry sliding conditions through block-on-ring wear tests. Microstructural and compositional effects on wear behaviour were studied by producing both equiaxed and elongated α sialons through the incorporation of additional oxides to promote extended liquid formation and grain growth, and by producing α / β composite materials with elongated β grains. The wear response of the materials is discussed in terms of the dominant wear mechanism under different experimental conditions. Under higher loads, where fracture dominates, materials with improved mechanical properties show better wear resistance and both the composite materials and the elongated α sialons showed lower wear rates than the equiaxed materials due to the elongated grain microstructures. Under low normal loads, fracture does not occur and the dominant wear mechanism is thought to be tribochemically assisted wear. Under these conditions, the equiaxed materials had better wear resistance than the composites, and the Lu-α sialon showed an order of magnitude lower wear rate than an equivalent Y-α sialon, thought to be due to better oxidation resistance and improved refractory nature afforded through the use of the smaller radius cation. The elongated Lu-α sialons under these low load conditions showed wear resistance that was to some extent dependent on the composition of the additional liquid phase, with high SiO2 contents leading to higher wear rates.

scholarly journals Microstructure Examination and Sliding Wear Behavior of Al-15%Mg2Si-xGd In Situ Composites before and after Hot Extrusion

Lubricants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 3
Author(s):  
Hamidreza Ghandvar ◽  
Mostafa Abbas Jabbar ◽  
Abdollah Bahador ◽  
Tuty Asma Abu Bakar ◽  
Nor Akmal Fadil ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Sliding Wear ◽  
Wear Behavior ◽  
Wear Test ◽  
Hot Extrusion ◽  
Wear Behaviour ◽  
High Wear Resistance ◽  
Wear Rates ◽  
Primary Mg2si ◽  
Before And After

In current study; the effect of various Gadolinium (Gd) additions on the microstructure and sliding wear behaviour of Al-15%Mg2Si composite before and after the hot extrusion process was examined. Optical microscopy (OM), scanning electron microscopy (SEM) equipped with EDX facility and X-ray diffraction (XRD) were used to characterize the microstructure. The results showed that with addition of 1.0 wt.% Gd to Al-15%Mg2Si composite, the primary Mg2Si particles size reduced from 44 µm to 23 µm and its morphology altered from dendritic to polygonal shape. Further refinement of primary Mg2Si particles was achieved after conducting hot extrusion which resulted in a decrease in its size to 19 µm with a transfer to near-spherical morphology. The Vickers hardness value increased from 55.6 HV in the as-cast and unmodified composite to 72.9 HV in the extruded 1.0% Gd modified composite. The wear test results revealed that composites treated with Gd possess higher wear resistance in comparison with those of without Gd. The highest wear resistance obtained with the lowest wear rates of 0.19 mm3/km and 0.14 mm3/km in the Al-15%Mg2Si-1.0% Gd before and after the hot extrusion, respectively. The high wear resistance of extruded Gd-modified Al-15%Mg2Si composite is due to the refinement of primary Mg2Si particles with uniform distribution in the composite matrix along with fragmentation of Gd intermetallic compounds.

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