scholarly journals Impact, Hardness and Fracture Morphology of Aluminium Alloy (Al-Si) filled Cobalt Oxide Nanoparticles at Various Stir Casting Temperatures

2021 ◽  
Vol 5 (1) ◽  
pp. 11-20
Author(s):  
Mardy Suhandani ◽  
Poppy Puspitasari ◽  
Jeefferie Abd Razak
Keyword(s):  
Impact Toughness ◽  
Melting Temperature ◽  
Impact Test ◽  
Casting Process ◽  
Fracture Morphology ◽  
Stir Casting ◽  
Impact Testing ◽  
Test Results ◽  
The Impact ◽  
Coo Nanoparticles

The automotive and aviation fields require engineering materials that can save and optimise fuel consumption. Unique characteristics of lightweight, higher strength to weight ratio, good corrosion resistance, and good castability are indispensable for castable metal such as Silicon Aluminium (Al-Si). The mechanical properties of Al-Si could be further improved through the addition of Cobalt Oxide (CoO) nanoparticles during the casting process. The importance and purpose of this study were to determine the impact toughness, hardness and fracture morphology of Al-Si metal alloy filled with 0.015 wt.% CoO nanofiller at the various melting temperature of 750 °C, 800 °C and 850 °C. The stir casting method was utilised considering the most appropriate method for mixing nanoparticles powder into the Al-Si matrix. Three test specimens were prepared for each temperature variation. Impact testing using the Charpy method (ASTM E23-56 T) and hardness testing using Rockwell Superficial HR15T and fracture morphology obtained from impact testing fractures were performed accordingly. The impact test results showed that the Al-Si added with 0.015% CoO at 800 °C of melting temperature possessed the highest impact toughness value of 25.111 x 10-3 Joule mm-2 than the other variations. The hardness test results showed that Al-Si added 0.015% CoO with a melting temperature of 850 °C had the highest hardness value of 79.52 HR15T. The fracture morphology of the impact test in all specimens shows uniform brittle fracture characteristics. It is found that the melting temperature during the stir-casting process of Al-Si has played a significant role in influencing the resulted properties of Al-Si filled CoO nanoparticles metal matrix composites. The selection of an accurate melting temperature for the stir casting process will affect the resulted properties of produced metal composites.

scholarly journals DYNAMIC IMPACT WEAR AND IMPACT RESISTANCE OF W-B-C COATINGS

2020 ◽  
Vol 27 ◽  
pp. 37-41
Author(s):  
Josef Daniel ◽  
Jan Grossman ◽  
Vilma Buršíková ◽  
Lukáš Zábranský ◽  
Pavel Souček ◽  
...  
Keyword(s):  
Impact Test ◽  
Impact Load ◽  
Protective Coatings ◽  
Impact Resistance ◽  
Impact Testing ◽  
The Novel ◽  
Test Results ◽  
Dynamic Impact ◽  
Impact Deformation ◽  
The Impact

Coated components used in industry are often exposed to repetitive dynamic impact load. The dynamic impact test is a suitable method for the study of thin protective coatings under such conditions. Aim of this paper is to describe the method of dynamic impact testing and the novel concepts of evaluation of the impact test results, such as the impact resistance and the impact deformation rate. All of the presented results were obtained by testing two W-B-C coatings with different C/W ratio. Different impact test results are discussed with respect to the coatings microstructure, the chemical and phase composition, and the mechanical properties. It is shown that coating adhesion to the HSS substrate played a crucial role in the coatings’ impact lifetime.

Effect of Nitrogen on the Impact Toughness of the Bearing Steel GCr15

2011 ◽  
Vol 311-313 ◽  
pp. 948-952
Author(s):  
Ji Chun Yang ◽  
Nan Liu
Keyword(s):  
Impact Toughness ◽  
Large Scale ◽  
Fracture Morphology ◽  
Bearing Steel ◽  
Impact Testing ◽  
Micro Cracks ◽  
Industrial Manufacture ◽  
Nitrogen Concentrations ◽  
Secondary Precipitates ◽  
The Impact

In order to explore the influence of the nitrogen concentrations on the impact toughness of the bearing steel GCr15，impact testing has been conducted on the steel samples with variant nitrogen contents (0.1-0.3 wt.%) on the tester JB－30B, and the fracture morphology of the samples after impact was investigated using scanning electron microscopy (SEM) and optical microscopy (OM). The results indicate that the impact toughness of the steel GCr15 with 0.1 wt.% nitrogen exhibits the lowest values with typical quasi-cleavage feature. The steel GCr15 with 0.2 wt.% nitrogen presents the maximum values in impact toughness associated with significant plastic deformation, suggesting ductile nature. The steel with 0.3 wt.% nitrogen presents a quasi-cleavage feature, and micro cracks observed beside the secondary precipitates. The impact toughness values of the steel with 0.3 wt.% nitrogen are higher than that with 0.1 wt.% nitrogen and lower than with 0.2 wt.% nitrogen. The results are valuable for a large-scale bench marked industrial manufacture of the bearing steel GCr15 with the optimized nitrogen concentrations.

Tempering Temperature Effects on Hardness and Impact Toughness of 56NiCrMo7 Steel

2011 ◽  
Vol 56 (1) ◽  
pp. 5-11 ◽  
Author(s):  
R. Dąbrowski ◽  
R. Dziurka
Keyword(s):  
Impact Toughness ◽  
Tool Steel ◽  
Impact Energy ◽  
Temperature Effects ◽  
Test Specimen ◽  
Impact Test ◽  
Test Results ◽  
Tempering Temperature ◽  
Fracture Surfaces ◽  
The Impact

Tempering Temperature Effects on Hardness and Impact Toughness of 56NiCrMo7 Steel The assessment of the effect of tempering temperature on hardness and impact toughness of a 56NiCrMo7 grade hot work tool steel was presented in the paper. It has been found that the investigated steel, after quenching in oil from 800°C, softens quite slowly upon tempering within the range between 100 and 675°C, which was confirmed not only by hardness measurements but also by observed changes occurring in its microstructure, whereas the impact energy (KV) absorbed by the test specimen increases with temperature, achieving >66J after tempering at 675°C. The changes observed in the character of the fracture surfaces allows of interpretation of the impact test results for the whole range of tempering temperatures.

scholarly journals Study of Impact Strength, Hardness, Micro Structure and Tribological Properties of Al5052 Composite with SiC and Graphite as Reinforcements

2020 ◽  
Vol 9 (9s) ◽  
pp. 7-10
Keyword(s):  
Impact Toughness ◽  
Wear Behavior ◽  
Base Alloy ◽  
Cast Alloy ◽  
Casting Process ◽  
Stir Casting ◽  
Wear Property ◽  
Wear Properties ◽  
Aluminum Composite ◽  
The Impact

Aluminum Composite are widely used in aviation and automotive industries because it is light in weight hence it reduces the fuel consumption and improves the energy efficiency. The present work deals with preparing Aluminum-based particle reinforced composite fabricated through Stir Casting Process wherein Sic along with Graphite are used as reinforcements which has improved mechanical properties with reduction in weight. Impact toughness, hardness along with wear property of the fabricated composite samples were tested and compared with Al 5052 Cast Alloy based on ASTM Standard. From the testing, we can conclude that Impact toughness, Hardness and wear properties of Al 5052 base alloy is considerably increased due to the addition of particulate reinforcements. And also there is not much studies reported on the influence of Sic and Graphite as reinforcement on Impact toughness, hardness along with Wear behavior of Al 5052 alloy. So the objective of the current work is to fabricate Al 5052 base alloy reinforced with particulate composite by stir casting process and to study the Impact toughness, hardness, and microstructure along with wear behavior of the fabricated composites.

Tribological characteristics of AA8090-WC-ZrC metal matrix composites prepared by stir casting process for Aerospace applications

2021 ◽  
Vol 73 (6) ◽  
pp. 980-985
Author(s):  
Kalaiyarasan A ◽  
Sundaram S ◽  
Gunasekaran K ◽  
Bensam Raj J.
Keyword(s):  
Metal Matrix ◽  
Materials Science ◽  
Scientific Information ◽  
High Hardness ◽  
Hardness Test ◽  
Casting Process ◽  
Stir Casting ◽  
Hybrid Particles ◽  
Content Type ◽  
The Impact

Purpose Aerospace field is demanding a material with superior strength and high resistance against wear, tear and corrosion. The current study aimed to develop a new material with high performance to be applicable in aerospace field Design/methodology/approach A metal matrix composite AA8090-WC-ZrC was fabricated using stir casting method and its tribological behavior was investigated. Totally, five composites viz. AA/Z, AA/W, AA/WZ (1:3), AA/WZ (1:1) & AA/WZ (3:1) were prepared. Micro hardness, tensile and wear study were performed on the fabricated composites and the results were compared with AA8090 alloy Findings Vickers hardness test resulted that the AA/W composite showed the higher hardness value of 160 HB compared to other materials due to the reinforcing effect of WC particles with high hardness. Tensile test reported that the AA/W composite displayed the maximum tensile strength of 502 MPa owing to the creation of more dislocation density. Further, wear study showed that the AA/W composite exhibited the least wear rate of 0.0011 mm3/m because of the more resisting force offered by the WC particles. Furthermore, the AA/W composite showed the slightest mass loss of 0.0028 g and lower COF value of 0.31 due to the hinder effect of WC particle to the movement of atoms in AA8090 alloy Originality/value This work is original in the field of aerospace engineering and materials science which deals with the fabrication of AA8090 alloy with the reinforcement particles such as tungsten carbide and zirconium carbide. The impact of the combination of hybrid particles and their volume fractions on the tribological properties has been investigated in this work. This work would provide new scientific information to society.

Analysis Method for Impact and Dispersion Behavior of Water-Filled Tank

2018 ◽  
Vol 4 (4) ◽  
Author(s):  
Hidekazu Takazawa ◽  
Kazuma Hirosaka ◽  
Katsumasa Miyazaki ◽  
Norihide Tohyama ◽  
Naomi Matsumoto
Keyword(s):  
Structural Damage ◽  
Impact Test ◽  
Velocity Ratio ◽  
Research Centre ◽  
Dispersion Pattern ◽  
Test Results ◽  
Analysis Method ◽  
Cylindrical Tank ◽  
Dispersion Behavior ◽  
The Impact

A new Japanese nuclear regulation involves estimating the possible damage to plant structures due to intentional aircraft impact. The effect of aircraft impact needs to be considered in the existing nuclear power plants. The structural damage and fuel dispersion behavior after aircraft impact into plant structures can be evaluated using finite element analysis (FEA). FEA needs validated experimental data to determine the reliability of the results. In this study, an analysis method was validated using a simple model such as a cylindrical tank. Numerical simulations were conducted to evaluate the impact and dispersion behavior of a water-filled cylindrical tank. The simulated results were compared with the test results of the VTT Technical Research Centre of Finland (VTT). The simulations were carried out using a multipurpose FEA code LS-DYNA®. The cylindrical tank was modeled using a shell element, and the tank water was modeled using smoothed particle hydrodynamics (SPH) elements. First, two analysis models were used to evaluate the effect of the number of SPH elements. One had about 300,000 SPH elements and the other had 37,000 SPH elements. The cylindrical tank ruptured in the longitudinal direction after crashing into a rigid wall, and the filled water dispersed. There were few differences in the simulated results when using different numbers of SPH elements. The VTT impact test was simulated with an arbitrary Lagrangian-Eulerian (ALE) element to consider the air drag. The analytical dispersion pattern and history of dispersion velocity ratio agreed well with the impact test results.

Effect of Hydrogen Content on Impact Property of A357 Alloy

2011 ◽  
Vol 704-705 ◽  
pp. 1201-1204 ◽  
Author(s):  
Yang Li ◽  
Zheng Bing Xu ◽  
Jian Min Zeng
Keyword(s):  
Crack Propagation ◽  
Hydrogen Content ◽  
Impact Test ◽  
Testing Machine ◽  
Initial Crack ◽  
Impact Testing ◽  
Total Absorption ◽  
A357 Alloy ◽  
Absorption Energy ◽  
The Impact

The impact specimens with different hydrogen contents were solution treated at 540±3°C for 12h; water quenched at 60-100°C; and aged at 165±1°C for 6h. The impact test was carried out at Roell450 pendulum impact testing machine. The impact test results show that the impact energy has strong relation with the hydrogen content. The total absorption energy increases with the increasing of hydrogen content. The crack propagation energy Avp and present larger proportion than the initial crack energy Avi in the total absorption energy Av. The number of the pinholes increases and the pinholes turn from smaller irregular ones into sub-circular shape ones. The specimen with irregular sub-circular pinholes has larger KI, and has more crack propagation resistance.

scholarly journals Evaluation of Microstructure and Impact Toughness of Shielded Metal Arc Dissimilar Weldments of High Strength Low Alloy Steel and Austenitic Stainless Steel

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Misbahu A Hayatu ◽  
Emmanuel T Dauda ◽  
Ola Aponbiede ◽  
Kamilu A Bello ◽  
Umma Abdullahi
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Toughness ◽  
Impact Energy ◽  
High Strength ◽  
Impact Testing ◽  
Welding Parameters ◽  
Dissimilar Weld ◽  
Weld Joints ◽  
The Impact

There is a growing interest for novel materials of dissimilar metals due to higher requirements needed for some critical engineering applications. In this research, different dissimilar weld joints of high strength low alloy (HSLA) and 316 austenitic stainless steel grades were successfully produced using shielded metal arc welding (SMAW) process with 316L-16 and E7018 electrodes. Five variations of welding currents were employed within the specified range of each electrode. Other welding parameters such as heat inputs, welding speeds, weld sizes, arc voltages and time of welding were also varied. Specimens for different weld joint samples were subjected to microstructural studies using optical and scanning electron microscopes. The impact toughness test was also conducted on the samples using Izod impact testing machine. The analysis of the weld microstructures indicated the presence of type A and AF solidification patterns of austenitic stainless steels. The results further showed that the weld joints consolidated with E7018 electrode presented comparatively superior impact energy to the weldments fabricated by 316L-16 electrode. The optimum impact energy of E7018-weld joints (51J) was attained at higher welding heat inputs while that of 316L-16-weld joints (35J) was achieved at lower welding heat inputs, which are necessary requirements for the two electrodes used in the experiment. Hence, the dissimilar weld joints investigated could meet requirement for engineering application in offshore and other critical environments.Keywords—Dissimilar metal weld, heat input, impact toughness, microstructures

Effect of Grain Size and Meso-Texture on the Impact Toughness of Ti-Microalloyed Steel

2011 ◽  
Vol 702-703 ◽  
pp. 766-769 ◽  
Author(s):  
A. Ray ◽  
Debalay Chakrabarti
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Impact Toughness ◽  
Microalloyed Steel ◽  
Charpy Impact ◽  
Impact Testing ◽  
Grain Sizes ◽  
Matrix Strength ◽  
Charpy Impact Testing ◽  
The Impact

Charpy impact testing (over the transition temperature rage) on different samples of a Ti-microalloyed steel, having the same average-TiN particle size but different average-ferrite grain sizes, showed that in spite of the presence of large TiN cuboides, ferrite grain refinement can significantly improve the impact toughness, provided the meso-texture (i.e. the intensity of low-angle boundaries) and matrix strength can be restricted to low values.

Hardness and Impact Toughness of Niobium Alloyed Austempered Ductile Iron

2011 ◽  
Vol 418-420 ◽  
pp. 1768-1771 ◽  
Author(s):  
Bulan Abdullah ◽  
Siti Khadijah Alias ◽  
Ahmed Jaffar ◽  
Rashiddy Wong Freddawati ◽  
A. Ramli
Keyword(s):  
Impact Toughness ◽  
Ductile Iron ◽  
Treatment Process ◽  
Impact Test ◽  
Induction Furnace ◽  
Hardness Test ◽  
Austempered Ductile Iron ◽  
Austenitizing Temperature ◽  
Austempering Temperature ◽  
The Impact

The effect of different austempering holding times on the hardness and impact toughness of 0.254% niobium alloyed austempered ductile iron was investigated in this study. Molten ductile iron was prepared in an induction furnace with capacity of 60kg. Samples with dimension of 300m x Ø25mm in form of Y block double cylinder was constituted and solidified samples were then machined in accordance to ASTM E23 for impact test specimens. Samples were ground and polished before Rockwell hardness test was conducted. Austempering heat treatment process with austenitizing temperature of 900°C for 1 hour and austempering temperature of 350°C for 1 hour, 2 hours and 3 hour holding times were then carried out. The results from this research indicated that austempering the sample for 1 hour resulted in significant improvement of the impact toughness values but increasing the austempering holding time deficiently reduced the values. On the contrary, the hardness of niobium alloyed austempered ductile iron continues to increase with respect to longer austempering holding times.

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