scholarly journals Identification and modelling of applicable wear conditions for stir cast Al-composite

Friction ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 847-873
Author(s):  
Santanu Sardar ◽  
Santanu Kumar Karmakar ◽  
Debdulal Das
Keyword(s):  
Orthogonal Design ◽  
Optimization Technique ◽  
Matrix Alloy ◽  
Stir Casting ◽  
Tribological Performance ◽  
Friction Coefficients ◽  
Wear Rates ◽  
Control Factors ◽  
Desirability Approach ◽  
Abrasive Size

Abstract A comprehensive study of the tribological performance of the Al-Zn-Mg-Cu/Al2O3 composite and its matrix alloy is presented in this paper, with a specific emphasis to identify and model the applicable wear conditions where the composite provides a minimum of 50% reduction in wear rate and 25% lowering of the friction coefficient. Two-body abrasion experiments following Taguchi L27 orthogonal design have been performed separately on alloy and composite materials, both prepared by the stir casting method. The influence of crucial control factors including silicon carbide (SiC) abrasive size, load, sliding distance, and velocity on the percentage variations of wear rates and friction coefficients between alloy and composite have been studied using the analysis of variance technique and full quadratic regression method. The dominant control factors are identified as abrasive size, load, and the interaction between abrasive size and load. This has been verified by establishing the influence of abrasive size and load on variations of wear mechanisms like microcutting, microploughing, and delamination, identified by means of in-depth characterization of worn surfaces and generated debris for both alloy and composite. The selection of applicable tribological condition for the composite has been accomplished by adopting the multi-response optimization technique based on combined desirability approach to obtain concurrent optimization of the percentage variations of wear rates and friction coefficients. Predictive models correlating the superiority of tribological performance of composite with abrasion conditions have been developed, and these are found to be accurate (errors <10%), as determined by confirmatory experiment.

scholarly journals Study on the Tribological Performance of Copper-Based Powder Metallurgical Friction Materials with Cu-Coated or Uncoated Graphite Particles as Lubricants

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2016 ◽  
Author(s):  
Xin Zhang ◽  
Yongzhen Zhang ◽  
Sanming Du ◽  
Zhenghai Yang ◽  
Tiantian He ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Friction Coefficient ◽  
Relative Density ◽  
Tribological Performance ◽  
Interfacial Bonding ◽  
Initial Test ◽  
Friction Coefficients ◽  
Wear Rates ◽  
Graphite Particles ◽  
Test Speed

The tribological performance of copper-based powder metallurgical material is much influenced by the interfacial bonding between the components and matrix. By adding Cu-coated or uncoated graphite particles as a lubricant, two types of copper-based powder metallurgical materials were prepared via spark plasma sintering (SPS). The hardness, relative density, and thermal conductivity of the two specimens were firstly measured. Using an inertial braking test bench and temperature measuring instrument, the average friction coefficients, instantaneous friction coefficients, and friction temperatures of the two specimens were tested under different test conditions, and the wear rates were calculated accordingly. Based on the analysis of surface morphologies and elements distribution after the tests, the mechanisms of wear and formation of friction films were discussed. The results show that with the lubricant of Cu-coated graphite, the hardness, relative density, thermal conductivity, and interfacial bonding between the graphite and matrix can be greatly improved. Under the same test condition, the average friction coefficient, wear rate, and friction temperature of the specimen with added Cu-coated graphite are both lower than those of the specimen with added uncoated graphite. The two specimens show different variation trends in the instantaneous friction coefficient during the tests, and the variation of the instantaneous friction coefficient at a high initial test speed is also different from that at a low initial test speed for each specimen. The two specimens also show differences in the continuity of friction film and the content of graphite and oxide in the friction film.

Study on Mechanical and Wear Behaviour of AA7075/TaC/Si3N4/Ti Hybrid Metal Matrix Composites

2022 ◽  
Vol 10 (1) ◽  
pp. 1-16
Author(s):  
J. Pradeep Kumar ◽  
D. S. Robinson Smart
Keyword(s):  
Elevated Temperatures ◽  
Optimization Technique ◽  
Matrix Material ◽  
Frictional Coefficient ◽  
Stir Casting ◽  
Tantalum Carbide ◽  
Wear Behaviour ◽  
Sliding Speed ◽  
Control Factors ◽  
Mechanical And Tribological Characteristics

This research article focuses on the development of AA7075 alloy reinforced with different wt% of Tantalum Carbide (TaC), Silicon Nitride (Si3N4) and Titanium (Ti) particulates using stir casting. Mechanical characteristics like tensile, compression and microhardness of the developed composites were analysed. High temperature tribological properties of the hybrid MMCs were studied for various input control factors like sliding speed, load and temperature. Design analysis has been executed by Taguchi orthogonal array and ANOVA (Analysis of Variance). The incorporated reinforcements exhibited improved wear resistance at ambient temperature along with elevated temperatures. Monolithic dissemination of reinforcement’s in the prepared composites magnifies the mechanical and tribological characteristics for composites compared to matrix material. From the optimization technique, it was witnessed that Wear Rate and Frictional Coefficient are afflicted by temperature go after load & sliding speed. The optimal amalgamation of control parameters of distinct tribo-responses has been detected.

Abrasive wear response of Al-Si–SiCp composite: Effect of friction heat and friction coefficient

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Raj Kumar Singh ◽  
Amit Telang ◽  
Satyabrata Das
Keyword(s):  
Heat Treatment ◽  
Friction Coefficient ◽  
Abrasive Wear ◽  
Applied Load ◽  
Frictional Heating ◽  
Matrix Alloy ◽  
Composite Effect ◽  
Friction Heat ◽  
Wear Response ◽  
Abrasive Size

Abstract The effects of friction heat and friction coefficient on the abrasive wear response of Al-7.5Si–SiCp composite against low-cost hypereutectic (Al-17.5Si) alloy were investigated as functions of the abrasive size and applied load in both as-cast and after heat-treatment conditions. Experiments were performed on pin-on-disc apparatus at 38 –80 μm abrasive size, 5 – 20 N applied load, 100 –400 m abrading (sliding) distances and 1 m s–1 constant sliding speed. The frictional heating of as-cast and heat-treated composite was superior compared to the matrix alloy and hypereutectic alloy, whereas the trend reversed for the friction coefficient. The frictional heating and friction coefficient of the materials increased with the abrasive size and applied load in both as-cast and after heat-treatment. The worn surface and wear debris particles were examined by using field emission scanning electron microscopy to understand the wear mechanism.

Tribological performance of self-lubricated polyamide6/boric oxide composites after water conditioning

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kawaljit Singh Randhawa ◽  
Ashwin Patel
Keyword(s):  
Friction Coefficient ◽  
Abrasion Resistance ◽  
Tribological Performance ◽  
Boric Oxide ◽  
Resistance Testing ◽  
Tribological Behaviour ◽  
Content Type ◽  
Wear Rates ◽  
Water Conditioning ◽  
Oxide Composites

Purpose This paper aims to investigate the tribological performance, i.e. abrasion resistance, friction coefficient and wear rates, of self-lubricated water conditioned polyamide6/boric oxide composites. Design/methodology/approach Polyamide6 and polyamide6/boric oxide self-lubricated composites were immersed in water for 15 days to analyze the effect of water conditioning on friction, wear and abrasion resistance. Tribological testing on pin-on-disc tribometer and abrasion resistance testing on TABER abrader were performed to see the friction coefficient and wear rates of materials. The scanning electron microscopy (SEM) characterizations were performed to analyze the wear tracks. Findings Tribological testing results revealed the loss in abrasive resistance, but there was an improvement in frictional coefficient and wear rates with steel after water absorption. The SEM images clearly show less depth of wear tracks in water-conditioned materials than dry ones. Water conditioning was found supportive in the formation of smooth lubricating transfer film on steel disc during the tribological testing. Originality/value The tribological behaviour of polymer composites is different in dry and in high humidity or water conditions. Experiments were performed to investigate B2O3 solid lubricant filler effectiveness on tribological behaviour of water-conditioned polyamide composites. Bonding between polyamide6 and water molecules plus the formation of orthoboric acid was found advantageous in decreasing the friction coefficient and wear rates of composites.

Study on Mechanical Property of Aluminium 6061 with E Glass Fiber Reinforced Composite

2018 ◽  
Vol 877 ◽  
pp. 50-53 ◽  
Author(s):  
Vinayashree ◽  
R. Shobha
Keyword(s):  
Mechanical Properties ◽  
Glass Fiber ◽  
High Strength ◽  
Matrix Alloy ◽  
Stir Casting ◽  
Reinforced Composite ◽  
Reinforcement Content ◽  
Glass Fiber Reinforced ◽  
The Matrix ◽  
Glass Fibre Reinforced

Aluminium composites are in predominant use due to their lower weight and high strength among the MMC’s. Aluminium 6061 is selected as matrix and E-glass fiber is selected as reinforcement. Fabrication of composite is done by stir casting method. Each fabrication carries the E-glass reinforcement content varied from 2% to 10%. The present article attempts to evaluate the mechanical properties of E-glass fibre reinforced composite and study the effect of reinforcement on the matrix alloy through mechanical properties. When compared to ascast mechanical properties the UTS has increased from 74.28 N/sq mm to 146.8 N/sq mm for a composite at 6% E-glass. The hardness of as-cast has also increased from 22 RHB to 43 RHB at 6% E-glass and the wear of composite has exhibited a decreasing tend with increase in reinforcement content along the sliding distance. The results are analyzed in certain depth in the current paper. The mechanical properties of composites have improved with the increase in the weigh percentage of glass fiber in the aluminium matrix.

Investigation of mechanical properties and tribological performance of Al-LSP and Al-Al2O3 composite

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lokanadham Dharmana ◽  
Venkata Subbaiah Kambagowni
Keyword(s):  
Mechanical Properties ◽  
Optimal Condition ◽  
Casting Process ◽  
Stir Casting ◽  
Tribological Performance ◽  
Connecting Rod ◽  
Content Type ◽  
Specific Strength ◽  
Error Band ◽  
Structural Applications

Purpose This study aims to develop the Al-Si-Mg metal matrix composite, reinforced distinctly with lime stone powder (LSP; 12% by weight) and Al2O3 (12% by weight), and compare their mechanical properties and tribological performance. Design/methodology/approach The composites are fabricated through stir casting process. In view of the previous work, the Al-LSP composite with LSP reinforcement (12 Wt.%) shows enhanced mechanical properties and tribological performance, as compared with other weight percentages. Findings Though the Al-LSP composite is less expensive, it shows similar hardness, tensile strength and specific strength, when compared with Al- Al2O3 composite. However, the Al-LSP composite exhibits significant enhancement of above three properties, when compared with Al-Si-Mg metal. The systematic factorial design of experiments is obtained through Taguchi OA [L9]. The tribological performance is estimated through wear rate (WR-mm3/m) and coefficient of friction (CF) by varying the operating parameters of sliding distance (SD), load (L) and sliding velocity (SV). According to ANOVA results, the optimal condition of WR for all the tested materials is L1SD3SV1. Further, the optimal condition of CF is L1SD1SV3 for Al-LSP and Al-Si-Mg metal, while L2SD3SV2 is for Al-Al2O3 composite. The regression equation predicts the measured experimental values within error band of ± 8 percentage. Originality/value A comparison of two composite materials (Al-LSP and Al-Al2O3) with same weight fractions (12%) shows almost same trend in both the mechanical and tribological testing process. However, the developed Al-LSP composite exhibited better properties than the Al-Al2O3 and Al-base. Therefore, Al-LSP can be suggested for automotive applications (i.e., connecting rod, cylinder liners, camshaft) and structural applications (such as frames, over hanging supports), without compromising in desirable original with properties of constituents in the new material, which is achievable for looking to the end uses.

Experimental study on friction coefficient and temperature rise of heavy-load grease-lubricated spherical plain bearings with surface texture

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jinlong Shen ◽  
Tong Zhang ◽  
Jimin Xu ◽  
Xiaojun LIU ◽  
Kun Liu
Keyword(s):  
Friction Coefficient ◽  
Temperature Rise ◽  
Surface Texture ◽  
Tribological Performance ◽  
Textured Surface ◽  
Textured Surfaces ◽  
Roughness Parameters ◽  
Heavy Load ◽  
Friction Coefficients ◽  
Content Type

Purpose This paper aims to improve the tribological performance of grease-lubricated spherical plain bearings (SPBs) under heavy load, dimple-type textures were prepared by laser on the outer surface of the inner ring. The influence of roughness parameters of a textured surface on reducing friction coefficient and temperature rise was also explored. Design/methodology/approach This study adopts a laser processing method to fabricate dimple-type textures. Three-dimensional roughness parameters were used to characterize the textured surfaces. The friction coefficients of five SPBs with surface texture and one original commercially available SPB without surface texture under different nominal loads were measured on a self-established test rig. The data of temperature rise were obtained by nine embedded thermal couples. Findings The results indicate that SPBs with textures generally exhibit lower friction coefficients than the original SPB without textures. The dimple depth has a significant influence on improving the tribological performance, which coincides with the analysis by surface roughness parameters. A textured surface with negative Ssk and high Vvc has the minimum temperature rise. Originality/value As it is too difficult to arrange sensors into heavy-load SPBs, there are few reports about the temperature characteristics. Through nine embedded thermal couples, the distribution of temperature rise on the inner ring of SPBs was given in this study. The positive effect of surface texture on reducing temperature rise and friction coefficient was verified, which is beneficial for the design of heavy-load SPBs.

Fabrication and Tribological Properties of Al-Si/B4C Metal Matrix Composites

2014 ◽  
Vol 2 (1) ◽  
pp. 74-84 ◽  
Author(s):  
Sadineni Rama Rao ◽  
G. Padmanabhan ◽  
P.V. Chandra Shekar Rao
Keyword(s):  
Friction Coefficient ◽  
Boron Carbide ◽  
High Strength ◽  
Casting Process ◽  
Stir Casting ◽  
Constant Load ◽  
Dry Sliding Wear ◽  
Al Alloy ◽  
Wear Rates ◽  
Line Wear

Aluminium composite materials are exponentially growing up and rapidly gaining importance because of their properties like low density, high strength, high stiffness, environmental resistance, low co-efficient of thermal expansion etc. In this context aluminum-boron carbide composites, with 2.5, 5 and 7.5 wt% of boron carbide (B4C) particulate reinforced, were prepared by stir casting process and the effect of the percentage of reinforcement of B4C on dry sliding wear and friction coefficient were investigated. The wear tests were carried out on a pin-on-disc type apparatus at a linear speed of 1m/s, sliding distance of 500 m and a constant load of 30 N. The coefficient of friction was recorded on line. Wear rates were calculated from mass loss measurements. Scanning electron microscope was used to examine the tribo-surface of worn Al- B4C composites. The results showed that the wear rate of 7.5 wt% B4C composites is 0.375 mg/min which is significantly lower than pure Al alloy (3.125 mg/min). The friction coefficient decreases from 0.477(for pure Al alloy) to 0.261(for 7.5 wt% B4C composites).

scholarly journals Influence of micro- and nanofiller contents on friction and wear behavior of epoxy composites

2017 ◽  
Vol 24 (4) ◽  
pp. 485-494 ◽  
Author(s):  
Iskender Ozsoy ◽  
Adullah Mimaroglu ◽  
Huseyin Unal
Keyword(s):  
Fly Ash ◽  
Friction And Wear ◽  
Filler Content ◽  
Wear Behavior ◽  
Tribological Performance ◽  
Epoxy Composites ◽  
Atmospheric Conditions ◽  
Wear Rates ◽  
Pin On Disc ◽  
Worn Surface

AbstractIn this study, the influence of micro- and nanofiller contents on the tribological performance of epoxy composites was studied. The fillers are micro-Al2O3, micro-TiO2, and micro-fly ash and nano-Al2O3, nano-TiO2, and nanoclay fillers. The microfillers were added to the epoxy by 10%, 20%, and 30% by weight. The nanofillers were added to the epoxy by 2.5%, 5%, and 10%. Friction and wear tests were conducted using the pin-on-disc arrangement. Tribo elements consisted of polymer pin and DIN 1.2344 steel counterface disc. A load value of 15 N, a sliding speed of 0.4 m/s, a sliding distance of 2000 m, and dry atmospheric conditions were applied to test conditions. The results show that the friction coefficients and the specific wear rates of the nanofilled composites increase as the filler content increases. For microfiller-filled epoxy composites, these values decrease as filler content increases. The tribological performance of epoxy composites is enhanced by the addition of microfillers, and the higher enhancement is reached with the addition of 30% fly ash filler. Finally, the pin and disc worn surface images show the presence of adhesive and some abrasive wear mechanisms.

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