Wear performance of Nb-alloyed, pulsed plasma nitrided Mo3Si intermetallic (original) (raw)
Related papers
Journal of Materials Science, 2008
Significant progress has been made in the past decade in plasma nitriding with a majority of the research work focusing on improving hardness and wear resistance of the nitrided surface through the reduction of nitriding temperature, pressure or time. Hard-solid lubricating coatings have also been extensively studied for lowering the wear rate and coefficient of friction of traditional hard coatings such as TiN by the combined effect of hardness and solid lubrication. In this study, the wear characteristics of low-temperature plasma-nitrided steel substrate performed using a Saddle-field fast atom beam source and TiN + MoS x hard-solid lubricant coating deposited by a closed-field magnetron-sputtering technique have been investigated. The thin hard layer in plasma-nitrided substrates exhibited much higher hardness and lower wear compared to the untreated substrate in pin-on-disc wear testing. In addition, the study of the wear track morphology of the nitrided samples evidenced significant reduction of deeper ploughing and plastic deformation due to higher hardness and load supporting of the nitrided layer. On the other hand, due to the incorporation of MoS 2 in TiN coating, the wear resistance and coefficient of friction were greatly improved in TiN + MoS x coating compared to pure TiN coating. In contrast to TiN coating, a relatively smoother wear track with less abrasive wear also supported the beneficial effects of adding MoS 2 in TiN coating.
Wear mechanisms and microstructure of pulsed plasma nitrided AISI H13 tool steel
Wear, 2010
a b s t r a c t AISI H13 tool steel discs were pulsed plasma nitrided during different times at a constant temperature of 400 • C. Wear tests were performed in order to study the acting wear mechanisms. The samples were characterized by X-ray diffraction, scanning electron microscopy and hardness measurements. The results showed that longer nitriding times reduce the wear volumes. The friction coefficient was 0.20 ± 0.05 for all tested conditions and depends strongly on the presence of debris. After wear tests, the wear tracks were characterized by optical and scanning electron microscopy and the wear mechanisms were observed to change from low cycle fatigue or plastic shakedown to long cycle fatigue. These mechanisms were correlated to the microstructure and hardness of the nitrided layer.
Friction and rolling–sliding wear of DC-pulsed plasma nitrided AISI 410 martensitic stainless steel
Wear, 2006
In the present work, industrial-scale DC-pulsed plasma nitriding for 20 h at 673 K was used to improve the wear resistance of an AISI 410 martensitic stainless steel. The tribological behaviour was studied and compared to the behaviour of the same steel in as-received condition. Pin-on-disc dry tests, using an alumina ball as counter-body, were carried out to determine the evolution of the friction coefficient. The wear resistance was investigated using an Amsler-disc-machine, employing a dry combined contact of rolling-sliding with three different applied loads. The wear mechanisms involved during rolling-sliding of unnitrided and plasma nitrided steels were investigated by microscopic observation of the surfaces, the corresponding cross-sections and the produced wear debris. The combination of different wear mechanisms taking place in the wear process of unnitrided and nitrided materials were discussed and analyzed. In contrast to the unnitrided steel, DC-pulsed plasma nitrided samples presented an improvement in the friction coefficient and the wear rate.
Wear, 1999
In our study, the friction and the wear behaviour of plasma and pulse plasma nitrided AISI 4140 steel was evaluated under dry sliding conditions, where hardened samples were used as a reference. The nitrided samples were fully characterised before and after the wear testing using metallographic, microhardness and surface examination techniques. After surface characterisation, dry sliding wear tests were performed on a pin-on-disc machine in which hardened ball bearing steel discs were mated to nitrided pins. The influence of sliding speed and contact load on the response of the surface treated pins was determined. The test results indicate, that the wear resistance of AISI 4140 steel can be improved by means of plasma and pulse plasma nitriding. However, compound layer should be removed from the nitrided surface to avoid impairment of the tribological properties by fracture of hard and brittle compound layer followed by the formation of hard abrasive particles. q 1999 Elsevier Science S.A. All rights reserved.
Tribological Performance of Plasma Nitrided Aisi 4140 Steel
Friction and wear characteristics of plasma nitrided discs in sliding wear contact against alumina were examined using a tribometer with a ball-on-disk configuration. The nitrided AISI 4140 samples were obtained by using the pulsed plasma nitriding process in a 1:4 H 2 -N 2 gas mixture at a temperature of 650K for 6h treatment time. Wear tests were performed at a sliding speed of 0.1 m.s -1 , 5 N load and 1000 m sliding distance. The tests were carried out at room temperature in air, without lubrication, by employing commercial alumina balls of 6 mm diameter as a static partner. A steady state friction coefficient of 0.87 was determined for this tribolgical pair. For comparison, the tribological behavior of substrate was also evaluated and a lower friction coefficient of 0.56 was found. The surface morphology and the topography of the wear scars have been determined by using both scanning electron microscopy and 3D stylus profilometry techniques. The wear resistance was evaluated by calculating the wear factor, k, considering than the volume is linearly proportional to the load and the sliding distance. Different wear mechanisms were detected such as abrasion, adhesion and oxidational wear for the pairs under study. Results have shown an improved wear resistance of the nitrided steel samples compared to the untreated ones.
Wear behavior of plasma nitrided AISI 420 stainless steel
International Journal of Materials Research, 2008
MartensiticA ISI 420 stainless steel wasplasmanitrided using aD CN 2 -H 2 pulsed discharge,a ftert hermaltreatmentattwodifferenttempering temperatures.Sliding wear behaviorw asdetermined bymeansof ab all-on-disktribometeratroom temperatureand without lubrication.Wear volume wascalculated from the information provided by ano pticalp rofilometerand wears cars wereanalyzed by ScanningElectron Microscopy.The results indicated that the nitridedsamplesexhibited improved wearr esistance when compared tothe untreated specimens,b ut corrosion resistancewasdiminished duetothe presenceo fthe outer nitrided layer.However,when thislayerwasremoved mechanicallyconsiderable improvementin the corrosionresistancewasachieved without impairing the wearr esistance of the whole system,whichwas200 %highercompared to the wearresistanceofthe non-nitrided specimens.
Behavior of the pulsed ion nitrided AISI 4140 steel/CVD TiN coatings as tribological pair
Thin Solid Films, 2000
The aim of the present investigation was to determine the effect of pulsed plasma nitriding process on the wear behavior of an AISI 4140 steel. Wear tests were performed using a ball-on-disc configuration with a linear sliding speed of 0.1 m s y1 , 5 N load and 700 m sliding distance. The tests were carried out at room temperature in air, without lubrication, by employing CVD TiN coated balls of 6 mm in diameter. The surface morphology and topography of the wear scars of samples and balls have been determined by using both scanning electron microscopy and three-dimensional stylus profilometry. Different wear mechanisms were detected such as abrasion, adhesion and oxidational wear for the pairs under study. Results have showed an improved wear resistance of the nitrided samples compared to the AISI 4140 steel samples. ᮊ
STUDY OF WEAR BEHAVIOR OF SS316LN USING PLASMA NITRIDING
The paper shows the consequences of an examination concerning the wear conduct of nitride 316LN austenitic tempered steel. The main scope of this study is to determine the wear, tensile strength and microstructure evaluation of the SS316LN plasma nitrating samples. The test was conducted where the plasma nitrating process was applied on the sample with different time periods and also compared with and without plasma nitrating sample. Wear test was directed utilizing pin on circle mechanical assembly to portray the conduct of austenitic treated steel. Nitrating is surface-hardening heat treatment that introduces nitrogen into the surface of steel at a temperature range of 500-550 C. It requires less time and lower temperature to provide distortion of work piece that carburizing.