Tribological and design parameters of lubricated sliding bearings

High performance, longevity and tribological behavior of lubricated sliding bearings are in close connection with selected design and tribological parameters. Among others, the most important are load carrying capacity dimensions, clearance, material and surface properties. Selection of these parameters is discussed and some recommendations in accordance with operating conditions are shown

Tribological and design parameters of lubricated sliding bearings

High performance, longevity and tribological behavior of lubricated sliding bearings are in close connection with selected design and tribological parameters. Among others, the most important are load carrying capacity dimensions, clearance, material and surface properties. Selection of these parameters is discussed and some recommendations in accordance with operating conditions are shown

Investigation of abrasive wear resistance of ferrous-based coatings with scratch tester

Abrasive wear resistance is very important in many applications and in most cases it is directly correlated with hardness of materials. Possible solutions for overcoming poor abrasive wear resistance of light metals, like Al-alloys, is using of coatings. In this paper the investigated results of the two types of ferrous-based coatings were presented and compared with gray cast iron, known as a material with good abrasive wear resistance. Process used for coating deposition on an Al-Si alloy substrate was Atmospheric Plasma Spraying (APS). Scratch tests with diamond indenter were used to simulate abrasive wear process. The indenter velocity of 10 mm/min was used over a wear tracks of 10 mm, with different normal loads applied. Both, coefficient of friction and wear rate of the samples were investigated and analyzed in correlation with its mechanical properties.

Tribological behaviour of Al-based MMCs and their application in automotive industry

The use of different kind of composite materials is in constant growing over the years, because they have better physical, mechanical and tribological properties comparing to matrix materials. Composite materials based on light metals like Aluminium, Magnesium and Zinc, due to their low density, find application in many industries. In automotive industry they are used for pistons, cylinders, engine blocks, brakes and power transfer system elements. This paper considers the tribological properties of Al-based MMCs as a function of the manufacturing technologies and variation of shape, dimension and percentage of reinforcement material

Investigation of abrasive wear resistance of ferrous-based coatings with scratch tester

Abrasive wear resistance is very important in many applications and in most cases it is directly correlated with hardness of materials. Possible solutions for overcoming poor abrasive wear resistance of light metals, like Al-alloys, is using of coatings. In this paper the investigated results of the two types of ferrous-based coatings were presented and compared with gray cast iron, known as a material with good abrasive wear resistance. Process used for coating deposition on an Al-Si alloy substrate was Atmospheric Plasma Spraying (APS). Scratch tests with diamond indenter were used to simulate abrasive wear process. The indenter velocity of 10 mm/min was used over a wear tracks of 10 mm, with different normal loads applied. Both, coefficient of friction and wear rate of the samples were investigated and analyzed in correlation with its mechanical properties.

Tribological behaviour of Al-based MMCs and their application in automotive industry

The use of different kind of composite materials is in constant growing over the years, because they have better physical, mechanical and tribological properties comparing to matrix materials. Composite materials based on light metals like Aluminium, Magnesium and Zinc, due to their low density, find application in many industries. In automotive industry they are used for pistons, cylinders, engine blocks, brakes and power transfer system elements. This paper considers the tribological properties of Al-based MMCs as a function of the manufacturing technologies and variation of shape, dimension and percentage of reinforcement material

Optimisation of the deposition parameters of thick atmospheric plasma spray coatings

Plasma spray process is one of the most versatile thermal spray deposition processes. There are great number of parameters that influence the quality and characteristic of deposited coating and their values must be defined precisely for each type of coating and used equipment particularly. A review of technology developed for deposition of ferrous-based powder spray (Fe-1.3Cr-1.5Mn-1.2C-0.3Ni, wt. %) on flat Al-Si alloy substrate surfaces is presented in this paper. Possible problems that may occur before and during the deposition process were pointed out as well as adequate solutions of those problems

Experimental investigation of viscosity of glycerol based nanofluids containing carbon nanotubes

The addition of solid nanoparticles to liquids provide significant enhancement of heat transfer and hydrodynamic flow. The viscosity of nanofluids is important for nanofluid transport related to flow dynamics and heat transfer. The aim of the paper is to investigate experimentally the viscosity of nanofluids prepared with glycerol base and nitrogen-doped bamboo shaped multi-walled carbon nanotubes (MWCNTs). The samples are prepared with 0.1, 0.2, 0.5 and 1.0 wt.% MWCNTs. The viscosity of glycerol and MWCNTs nanofluid suspensions are measured at various temperatures and rotational speeds (shear rates). The influence of nanotubes amount, temperature and rotational speed on the viscosity is investigated

Thermal cycling behaviour of plasma sprayed nicr-al-co-y2o3 bond coat in thermal barrier coating system

The aim of this study was to investigate the thermal cycling behaviour of NiCr-Al-Co-Y2O3 bond coating in thermal barrier coating (TBC) system with ZrO2-MgO as a top coating. The coatings were deposited by atmospheric plasma spraying (APS) on stainless steel X15Cr13 (EN 1.4024) substrate. The used composite powder NiCr-Al-Co-Y2O3 was mechanically cladded, and the steel substrates were preheated to 160-180 degrees C. The thermal cycling performance of the obtained bond coat and the effect of formed complex ceramic oxides of the Al2O3-Y2O3 system were tested by heating to 1200 degrees C and cooling in air to 160-180 degrees C. The number of performed thermal cycles was 7, 32 and 79. The quality of the obtained coating, as well as its thermal cycling behaviour, was assessed through the microstructural analysis, microhardness and tensile bond strength measurements, and change in chemical composition and microhardness. The obtained results showed that the steel substrate, bond coat oxidation and interdiffusion at bond coat/substrate interface have a significant influence on changes in chemical composition and microhardness of the bond coat. The correlation between oxidation behaviour of NiCr-Al-Co-Y2O3 bond coat and number of thermal cycles was also discussed

MMCs based on hypoeutectic Al-Si alloy: Tribological properties in dry sliding conditions

This paper presents a short summary of the researches conducted in past few years concerning the MMCs with A356 Al-Si alloy matrix and different second phase. The results are divided in two groups. In the first group are the results that concern the influences of amount and size of reinforcement (Al2O3), and in the second group are the results that concern the influences of type of reinforcement (Al2O3 and SiC) and graphite