Study on high-temperature wear and mechanism of Al-Si/graphite composites prepared by the die-casting process

2020 ◽  
Vol 72 (10) ◽  
pp. 1153-1158 ◽  
Author(s):  
Yafei Deng ◽  
Xiaotao Pan ◽  
Guoxun Zeng ◽  
Jie Liu ◽  
Sinong Xiao ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Peer Review ◽  
Die Casting ◽  
Casting Machine ◽  
Injection Pressure ◽  
Casting Process ◽  
Matrix Alloy ◽  
Content Type ◽  
The Matrix

Purpose This paper aims to improve the tribological properties of aluminum alloys and reduce their wear rate. Design/methodology/approach Carbon is placed in the model at room temperature, pour 680°C of molten aluminum into the pressure chamber, and then pressed it into the mold containing carbon felt through a die casting machine, and waited for it to cool, which used an injection pressure of 52.8 MPa and held the same pressure for 15 s. Findings The result indicated that the mechanical properties of matrix and composite are similar, and the compressive strength of the composite is only 95% of the matrix alloy. However, the composite showed a low friction coefficient, the friction coefficient of Gr/Al composite is only 0.15, which just is two-third than that of the matrix alloy. Similarly, the wear rate of the composite is less than 4% of the matrix. In addition, the composite can avoid severe wear before 200°C, but the matrix alloy only 100°C. Originality/value This material has excellent friction properties and is able to maintain this excellent performance at high temperatures. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0454/

Fretting wear behavior of WS2/ultra-high molecular weight polyethylene nanocomposites

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xiaocui Xin ◽  
Yunxia Wang ◽  
Zhaojie Meng ◽  
Hao Liu ◽  
Yunfeng Yan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Peer Review ◽  
High Molecular Weight ◽  
Fretting Wear ◽  
Specific Wear Rate ◽  
Wear Performance ◽  
Content Type ◽  
Ultra High Molecular Weight

Purpose This paper aims to focus on studying the addition of nano-tungsten disulfide (WS2) on fretting wear performance of ultra-high-molecular-weight-polyethylene (UHMWPE). Design/methodology/approach In this study, the effect of WS2 content on fretting wear performance of UHMWPE was investigated. The fretting wear performance of the UHMWPE and WS2/UHMWPE nanocomposites were evaluated on oscillating reciprocating friction and wear tester. The data of the friction coefficient and the specific wear rate were obtained. The worn surfaces of composites were observed. The transfer film and its component were analyzed. Findings With the addition of 0.5% WS2, the friction coefficient and specific wear rate increased. With the content increased to 1% and 1.5%, the friction coefficient and specific wear rate decreased. The lowest friction coefficient and specific wear rate were obtained with the addition of 1.5% nano-WS2. Continuingly increasing content, the friction coefficient and wear rate increased but lower than that of pure UHMWPE. Research limitations/implications The research indicated the fretting wear performance related to the content of nano-WS2 with the incorporation of WS2 into UHMWPE. Practical implications The result may help to choose the appropriate content. Originality/value The main originality of the research is to reveal the fretting behavior of UHMWPE and WS2/UHMWPE nanocomposites. It makes us realize the nano-WS2 had an effect on the fretting wear performance of UHMWPE. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2020-0151/

An experimental study on the tribological performance of water-lubricated journal bearings with three different materials

2020 ◽  
Vol 72 (10) ◽  
pp. 1159-1165
Author(s):  
Yanfeng Han ◽  
Lei Yin ◽  
Guo Xiang ◽  
Guangwu Zhou ◽  
Haizhou Chen ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Peer Review ◽  
Tribological Behavior ◽  
Operating Conditions ◽  
Butadiene Rubber ◽  
Test Rig ◽  
Vibration Acceleration ◽  
Content Type ◽  
Rubber Bearing

Purpose The tribological behavior, i.e. friction coefficient and wear rate, and vibration characteristics of the water-lubricated bearing was investigated. The water-lubricated bearing is made of three different materials, i.e. polyether-ether-ketone (PEEK), polyimide (PI) and nitrile-butadiene rubber (NBR). Design/methodology/approach The tribological behavior was investigated experimentally on a specially designed test rig. Three vibration sensors were used to record the vibration of the bearing. Findings The results indicated that the variation of friction coefficient with rotation speed agrees well with the trend of Stribeck curve. The tested friction coefficient of rubber bearing is higher than that of the other two bearings whether it is in the state of mixed-lubrication or hydrodynamic lubrication, and which causing a larger wear rate in rubber bearing. The PEEK bearing exhibits the best tribological properties due to it has smaller friction coefficient and wear rate. However, it can be found that the rubber bearing gives the minimum vibration acceleration, which means that the rubber bearing has the most potential to improve the stability of water-lubricated bearing rotor system. Originality/value In this study, a group of experiment studies conducted on a specially designed test rig. The comprehensive performance, including friction coefficient, vibration acceleration and wear rate, of water-lubricated bearing with three different materials, i.e. PEEK, PI and NBR, was compared systematically. The experiment research may offer a reference for the selection of material in water-lubricated bearing in specific operating conditions. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0447/

Tribological behaviors of the water-lubricated rubber bearings under different lubricated conditions

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bin Xiao ◽  
Xiaolin Zheng ◽  
Yi Zhou ◽  
Dan Yao ◽  
Yang Wan
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Peer Review ◽  
Design Methodology ◽  
Tribological Behavior ◽  
Friction Test ◽  
Content Type ◽  
Rubber Bearing ◽  
Rubber Bearings ◽  
Worn Surface

Purpose This study aims to evaluate the tribological behavior of water-lubricated rubber bearings sliding against stainless steel under different lubricate conditions. Design/methodology/approach The water-lubricated rubber bearings under various normal loads and sliding speeds were carried out on the ring-block friction test, and the wear morphology is test conducted by using scanning electron microscope. Findings The results indicate that the surface of water-lubricated rubber bearings has a more alternative friction coefficient and wear rate under seawater than other lubricate conditions. The seawater not only acts as a lubricating medium but also brings microstructure while corroding the rubber interface, thereby further enhancing the lubricating effect and storing abrasive debris. Originality/value In this paper, tribological properties of the water-lubricated rubber bearing on ring-block friction test has been investigated. Water-lubricated rubber bearing was carried out on various lubricate conditions, and the friction coefficient, wear rate and worn surface were analyzed. Also, the effects of sliding speeds were investigated. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-06-2020-0204/

A study on tribological behaviour and analysis of ZnO reinforced AA6061 matrix composites fabricated by stir casting route

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sakthi Sadhasivam RM ◽  
Ramanathan K. ◽  
Bhuvaneswari B.V. ◽  
Raja R.
Keyword(s):  
Wear Rate ◽  
Sliding Wear ◽  
Stir Casting ◽  
Industrial Applications ◽  
Wear Behaviour ◽  
Matrix Composites ◽  
Tribological Behaviour ◽  
Content Type ◽  
Zno Particles ◽  
The Matrix

Purpose The most promising replacements for the industrial applications are particle reinforced metal matrix composites because of their good and combined mechanical properties. Currently, the need of matrix materials for industrial applications is widely satisfied by aluminium alloys. The purpose of this paper is to evaluate the tribological behaviour of the zinc oxide (ZnO) particles reinforced AA6061 composites prepared by stir casting route. Design/methodology/approach In this study, AA6061 aluminium alloy matrix reinforced with varying weight percentages (3%, 4.5% and 6%) of ZnO particles, including monolithic AA6061 alloy samples, is cast by the most economical fabrication method, called stir casting. The prepared sample was subjected to X-ray photoelectron spectroscopy (XPS) analysis, experimental density measurement by Archimedian principle and theoretical density by rule of mixture and hardness test to investigate mechanical property. The dry sliding wear behaviour of the composites was investigated using pin-on-disc tribometer with various applied loads of 15 and 20 N, with constant sliding velocity and distance. The wear rate, coefficient of friction (COF) and worn surfaces of the composite specimens and their effects were also investigated in this work. Findings XPS results confirm the homogeneous distribution of ZnO microparticles in the Al matrix. The Vickers hardness result reveals that higher ZnO reinforced (6%) sample have 34.4% higher values of HV than the monolithic aluminium sample. The sliding wear tests similarly show that increasing the weight percentage of ZnO particles leads to a reduced wear rate and COF of 30.01% and 26.32% lower than unreinforced alloy for 15 N and 36.35% and 25% for 20 N applied load. From the worn surface morphological studies, it was evidently noticed that ZnO particles dispersed throughout the matrix and it had strong bonding between the reinforcement and the matrix, which significantly reduced the plastic deformation of the surfaces. Originality/value The uniqueness of this work is to use the reinforcement of ZnO particles with AA6061 matrix and preparing by stir casting route and to study and analyse the physical, hardness and tribological behaviour of the composite materials.

Semisolid Die-Casting Process of Mg-20Al-0.8Zn Magnesium Alloy

2011 ◽  
Vol 306-307 ◽  
pp. 539-543
Author(s):  
Feng Yun Yan ◽  
Xiao Feng Huang ◽  
Bo Li ◽  
Ying Ma
Keyword(s):  
Tensile Strength ◽  
Die Casting ◽  
Injection Pressure ◽  
Casting Process ◽  
Elongation Rate ◽  
Isothermal Heat Treatment ◽  
Technological Parameters ◽  
Injection Speed ◽  
Die Casting Process ◽  
Spherical Grains

Based on microstructure evolution of Mg-20Al-0.8Zn magnesium alloys realized by semisolid isothermal heat-treatment (SSIT), we obtained the non-dendrite or spherical grains microstructure under the suitable technological parameters that isothermal temperature is 495 °C and holding time is 120 min. With the help of special experimental equipment, the semisolid die-casting process has been studied and the specimens have been analyzed. The effects of different parameters as injection speed and pressure on tensile strength, elongation rate, hardness, etc have been investigated. The results indicate that tensile strength was improved along with increasing injection speed and pressure. However, excessive speed will involve gas, which formed defects and reduced the mechanical properties. When the injection pressure is 40MPa and injection speed is 4m/s, the tensile strength and elongation rate can reach maximal 220MPa and 5.63% respectively. Its fracture mechanism was intercrystalline cracking.

scholarly journals Influence of load and reinforcement content on selected tribological properties of Al/SiC/Gr hybrid composites

2018 ◽  
Vol 18 (18) ◽  
pp. 18-23 ◽  
Author(s):  
Sandra Veličković ◽  
Slavica Miladinović ◽  
Blaža Stojanović ◽  
Ružica R. Nikolić ◽  
Branislav Hadzima ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Metal Matrix ◽  
Hybrid Composites ◽  
Tribological Characteristics ◽  
Volume Fractions ◽  
Sic Particles ◽  
The Matrix

Abstract Hybrid materials with the metal matrix are important engineering materials due to their outstanding mechanical and tribological properties. Here are presented selected tribological properties of the hybrid composites with the matrix made of aluminum alloy and reinforced by the silicon carbide and graphite particles. The tribological characteristics of such materials are superior to characteristics of the matrix – the aluminum alloy, as well as to characteristics of the classical metal-matrix composites with a single reinforcing material. Those characteristics depend on the volume fractions of the reinforcing components, sizes of the reinforcing particles, as well as on the fabrication process of the hybrid composites. The considered tribological characteristics are the friction coefficient and the wear rate as functions of the load levels and the volume fractions of the graphite and the SiC particles. The wear rate increases with increase of the load and the Gr particles content and with reduction of the SiC particles content. The friction coefficient increases with the load, as well as with the SiC particles content increase.

Friction coefficient study of nanocomposite Al2O3–NbC obtained by spark plasma sintering-SPS

2020 ◽  
Vol 72 (9) ◽  
pp. 1087-1094
Author(s):  
Susan Meireles C. Dantas ◽  
Marcio G. Di Vernieri Cuppari ◽  
Vania Trombini Hernandes
Keyword(s):  
Friction Coefficient ◽  
Peer Review ◽  
Spark Plasma Sintering ◽  
Contact Region ◽  
Content Type ◽  
3D Profilometry ◽  
Plasma Sintering ◽  
Dry Conditions ◽  
Spark Plasma ◽  
Surface Changes

Purpose This study aims to investigate the friction coefficient of Al2O3–NbC nanocomposite obtained by spark plasma sintering sliding against a steel ball. Design/methodology/approach Tribological tests were carried out using a reciprocating nanotribometer in a ball on flat configuration with normal loads in the range from 10 to 100 mN under dry conditions. Surface changes were analyzed by confocal microscopy and 3D profilometry. Findings The values of the friction coefficient varied from 0.15 to 0.6 and are independent of the applied load. Originality/value The tribological behavior is attributed to fracture in the contact region and the effect of wear debris. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2019-0356/

Fabrication and characterization of TiB2-reinforced functionally graded aluminum matrix material

2020 ◽  
Vol 72 (10) ◽  
pp. 1147-1152
Author(s):  
Ömer Savaş
Keyword(s):  
Wear Rate ◽  
Abrasive Wear ◽  
Peer Review ◽  
Centrifugal Force ◽  
Matrix Material ◽  
Aluminum Matrix ◽  
Functionally Graded ◽  
Aluminum Matrix Composites ◽  
Content Type

Purpose This study aims to investigate the production and abrasive wear rate of functionally graded TiB2/Al composites. TiB2 particles have been spontaneously formed in liquid matrix using in situ technique. The properties of composites such as hardness, abrasive wear rate and microstructure have been examined. Design/methodology/approach In situ TiB2 reinforcement phase was synthesized by using a liquid Al–Ti–B system. A semi-solid composite (Al(l)-TiB2(s)) prepared at 900°C was solidified under a centrifugal force to both grade functionally and give the final shape to materials. Abrasive wear test of materials was conducted using the pin-on-disk method at room temperature. The wear tests were carried out with two different loads of 1 Newton (N) and 2 N, a sliding velocity of 3.5 m s−1 and a sliding distance of 75 m. Findings This research provided the following findings; TiB2 particles can be successfully synthesized with in situ reaction technique in molten aluminum. It was determined that abrasive wear rate increases with increasing load and decreases with increasing TiB2 reinforcement content within matrix. Originality/value In previous studies, there have been many trials on the in situ production of TiB2-reinforced aluminum matrix composites. However, there are few studies on production of in situ TiB2-reinforced aluminum matrix functionally graded materials. At the same time, there is no study that the properties of composite, such as hardness and abrasive wear rate, are examined together according to centrifugal force. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2019-0538/

scholarly journals Reduction of Blowholesin Aluminium High Pressure Die Casting Machine

2018 ◽  
Vol 7 (3.34) ◽  
pp. 410
Author(s):  
Nagasankar P ◽  
Sathiyamoorthy. V ◽  
Gurusamy. P ◽  
VinothKanna P ◽  
Manibharathi D ◽  
...  
Keyword(s):  
High Pressure ◽  
Manufacturing Process ◽  
Die Casting ◽  
Casting Machine ◽  
Casting Process ◽  
Magma Flow ◽  
High Pressure Die Casting ◽  
Analysis Technique ◽  
Quality Product ◽  
Pressure Die Casting

The main objective of this research is to reduce the blowholes by analyzing the factors which are affected during the casting process. The process parameters are optimized and change is made in the design part to reduce the blowhole and to increase the efficiency of the high pressure die casting machines. Product manufactured from every manufacturing process shows some defects. For supplying quality product to the customer these defects must be reduced. In this work, an attempt is made to reduce the rejection due to the blowhole defect is found out through why-why analysis technique. Process capability of current high pressure die casting manufacturing process is checked. Manufacturing process found capable to manufacture the components. Current problem of blowhole defect is solved making an improvement in design of die which we insert. In gate directions are changed so as to obtain modified improved flow pattern. Using magma flow simulationsoftware existing and modified design has then been compared. It is found that, modified design shows superior results and using this, the defect of blowholes is minimized up to satisfactory level.   

Quality Control System for Die Castings Based on Statistic Analysis

2012 ◽  
Vol 246-247 ◽  
pp. 918-923
Author(s):  
Xiao Fang Ruan
Keyword(s):  
Quality Control ◽  
Control System ◽  
Statistical Analysis ◽  
Die Casting ◽  
Ferrous Metal ◽  
Casting Machine ◽  
Casting Process ◽  
Quality Control System ◽  
Die Castings

Die casting technology is applied widely for mass production of non-ferrous metal parts. How to guarantee the quality of die castings is always a concerned topic. A quality control system for die casting machine was developed based on statistical analysis of technology parameters. Firstly the original data is acquired from die casting machine and the technology curves are displayed. Secondly, the technology parameters are identified automatically and a database of technology parameters is established. Thirdly, a statistical analysis based on the database is performed. The statistics parameters of expecta -tion and deviation are figured out and the probability distribution diagrams for technology parameters are displayed. Finally, Tolerances for technology parameters are figured out and then the system will monitor the die casting process according to the tolerances. A practical system realization in a die casting machine is demonstrated by its monitoring interfaces. Statistical information and on-line monitoring provided by this system are helpful to guarantee the quality of die castings.

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