Hard Alloys with High Content of WC and TiC—Deposited by Arc Spraying Process

Obtained by different spraying technologies: in atmospheric plasma spray, High Velocity Oxygen Fuel (HVOF) or laser cladding, the layers of hard alloys with a high content of WC and TiC find their industrial applications due to their high hardness and resistance to wear. Recognized as being a process associated with welding, the arc spraying process is a method applied industrially both in obtaining new surfaces and for reconditioning worn ones. This chapter presents the technology for obtaining ultra-hard layers based on WC and TiC - by the arc spraying process, using a classic spray device equipped with a conical nozzle system and tubular wire additional material containing ultra-hard compounds (WC, TiC). To study both the quality of deposits and the influence of thermal spray process parameters on the properties of deposits with WC and TiC content, we approached various investigative techniques, such as optical scanning microscopy (SEM), X-ray diffraction, and determination of adhesion, porosity, Vickers micro-hardness and wear resistance

Experimental investigation on wear resistance of a new cutting fluid using a four ball tribometer – optimization of additive percent

The cutting fluid manufacturers aim to obtain the best products at the lowest possible price. To achieve such a compromise experimental work is needed, trying to get the lowest allowed content of additive in the base oil. The paper presents the results of standard tests carried out on four ball machine. This tribometer is used to analyze the load-carrying properties of cutting fluids. The results are compared with the standard requirements, related to the measured wear scar on the three lower balls of the four ball device. An optimum of sulphur additive content into the base oil was found around 10%. According to the actual standards and following the results of carried-out tests, for this specific case the lowest acceptable content of additive is around 4%

Experimental investigation on wear resistance of a new cutting fluid using a four ball tribometer – optimization of additive percent

The cutting fluid manufacturers aim to obtain the best products at the lowest possible price. To achieve such a compromise experimental work is needed, trying to get the lowest allowed content of additive in the base oil. The paper presents the results of standard tests carried out on four ball machine. This tribometer is used to analyze the load-carrying properties of cutting fluids. The results are compared with the standard requirements, related to the measured wear scar on the three lower balls of the four ball device. An optimum of sulphur additive content into the base oil was found around 10%. According to the actual standards and following the results of carried-out tests, for this specific case the lowest acceptable content of additive is around 4%

Wear and Rolling Contact Fatigue Analysis of AISI 52100 Bearing Steel in Presence of Additivated Lubricants

Tribological properties of lithium potassium titanate (PT), molybdenum disulphide, and tungsten disulphide-dispersed mineral oil (MO) were investigated. The sample containing 2 wt.% WS2 exhibited the lowest coefficient of friction. However, the wear scar diameters of the additivated samples were very narrow. Extreme pressure properties of mineral oil were enhanced with the addition of additives. The rolling contact fatigue results exhibited better fatigue life of the balls in MoS2 and PT-dispersed MO. Surface characterization of the balls indicated more pitting on the balls of the MO and WS2-dispersed MO as compared to MoS2 and PT, indicating a stable film in the case of MoS2 and PT, which was confirmed by the presence of additives on ball surfaces by Raman spectrograph. The results of extended rolling contact fatigue tests proved that PT-added mineral oil provided the highest life cycles of the tested balls, followed by MoS2 and WS2-added mineral oil; thus, indicating PT as a plausible alternative to MoS2 and WS2

Prediction of Roller Skewing in Tapered Roller Bearings

International audienc

Tribological Behavior and Microstructural Analysis of Atmospheric Plasma Spray Deposited Thin Coatings on Cardan Cross Spindles

Cardan joints are used in transmissions between misaligned shafts, as in all-wheel-drive (AWD) cars and railway applications. Their functioning is accompanied by heavy cyclical loads, with the cardan cross spindles subjected to intensive abrasive wear and pitting. In this paper, a solution to the mentioned issue is proposed, thin anti-wear coatings of Metco 32 and Metco 72 metallic powders deposited by atmospheric plasma spray (APS) on cylindrical samples cut from spindles of two cardan crosses made of 40Cr10 and RUL2 steel. The morphological analysis of the coated surfaces was realized by scanning electron microscopy (SEM), and the elemental composition of the tested samples was elaborated by energy-dispersive X-ray spectroscopy (EDS). To investigate the wear resistance of the coated samples in dry and grease-lubricated conditions, tests at constant load and constant speed were carried out using an AMSLER tribometer. The results of greased tests proved that the expulsion of the lubricant from the tribological contact occurred no matter the combination of coated or uncoated samples. During grease-lubricated tests of ten minutes, the least coefficient of friction was measured for uncoated specimens with better surface finishing; but in dry friction tests, the lowest values of the mean friction coefficients were obtained for the Metco 72 coatings. The porous coatings may act as lubricant reservoirs in long-lasting tests, providing a solution to the expulsion phenomenon of the lubricant to the boundary outside the area of the larger-diameter roller

Microstructural and Wear Properties of Annealed Medium Carbon Steel Plate (EN8) Cladded with Martensitic Stainless Steel (AISI410)

Limited work on the wear properties of martensitic stainless-steel weld clads initiated this work which included investigations on microstructural and wear properties of cladded AISI 410 (filler wire)/EN 8 plates (substrate). Three layers of martensitic stainless steel (AISI 410) were deposited using metal inert gas (MIG) welding on medium carbon steel (EN 8) achieving a 51.5 ± 2.35 HRC of top layer. The elemental and phase fractions of the cladded layers indicated 98% martensite phase and retained austenite (2%). About 40% dilution was observed between EN 8 and the first weld layer. The results of tests carried out on pin on disc tribometer revealed an enhancement of anti-wear life of the martensitic weld cladded EN 8 by three times that of uncladded EN 8. The uncladded EN 8 plate suffered severe damage and high wear, leading to its failure at 478 s. The failure of the uncladded EN 8 sample was identified by the occurrence of high vibration of the pin on disc tribometer which ultimately stopped the tribometer. On the other hand, the cladded EN 8 sample continued running for 3600 s, exhibiting normal wear. After the tribo test, the surfaces of the pins of both cladded and uncladded EN 8 were analyzed using scanning electron microscope (SEM) and 3D profilometer. The surface characterization of tribo pairs indicated ploughing and galling to be the primary wear mechanisms. The average grain size of top and middle layer was in the range of 2–3.5 µm, while the base metal showed 5.02 µm mean grain size, resulting in higher hardness of clad layers than base metal, also favoring better wear resistance of the cladded EN 8 samples as compared to uncladded EN 8 samples

Microstructural and Wear Properties of Annealed Medium Carbon Steel Plate (EN8) Cladded with Martensitic Stainless Steel (AISI410)

Limited work on the wear properties of martensitic stainless-steel weld clads initiated this work which included investigations on microstructural and wear properties of cladded AISI 410 (filler wire)/EN 8 plates (substrate). Three layers of martensitic stainless steel (AISI 410) were deposited using metal inert gas (MIG) welding on medium carbon steel (EN 8) achieving a 51.5 ± 2.35 HRC of top layer. The elemental and phase fractions of the cladded layers indicated 98% martensite phase and retained austenite (2%). About 40% dilution was observed between EN 8 and the first weld layer. The results of tests carried out on pin on disc tribometer revealed an enhancement of anti-wear life of the martensitic weld cladded EN 8 by three times that of uncladded EN 8. The uncladded EN 8 plate suffered severe damage and high wear, leading to its failure at 478 s. The failure of the uncladded EN 8 sample was identified by the occurrence of high vibration of the pin on disc tribometer which ultimately stopped the tribometer. On the other hand, the cladded EN 8 sample continued running for 3600 s, exhibiting normal wear. After the tribo test, the surfaces of the pins of both cladded and uncladded EN 8 were analyzed using scanning electron microscope (SEM) and 3D profilometer. The surface characterization of tribo pairs indicated ploughing and galling to be the primary wear mechanisms. The average grain size of top and middle layer was in the range of 2–3.5 µm, while the base metal showed 5.02 µm mean grain size, resulting in higher hardness of clad layers than base metal, also favoring better wear resistance of the cladded EN 8 samples as compared to uncladded EN 8 samples

Comportement rhéologique et tribologique de lubrifiants avec additif polymère

Du polyéthylène a été ajouté à trois huiles minérales. On a étudié l’influence du polymère sur le comportement rhéologique et tribologique du lubrifiant. Les résultats expérimentaux montrent que la concentration du polymère a un rôle important sur l’obtention de l’épaisseur maximum du film et sur la prévention de l’usure dans les contacts EHD. Le polymère forme un film lié à la surface, dont l’épaisseur est de l’ordre du diamètre de la pelote macromoléculaire. Ce film de polymère adsorbé à la surface des solides améliore les performances du lubrifiant (l’épaisseur du film, la résistance à l’usure ou le comportement en traction)

Application of Integrated BWM Fuzzy-MARCOS Approach for Coating Material Selection in Tooling Industries

The life of metal forming dies and the efficiency of tooling industries depends on the mechanical and wear properties of tool steel. These properties can be further improved by depositing the ceramic coating on heat-treated tool steel. Numerous coating materials with various excellent features are already available commercially; however, the selection of the best coating material is still an immense challenge for users. Compared to various studies related to material selection problems in the contrasting area of utilization, remarkably, little research work has been done in tooling industries. In the present work, we have identified eight coating materials (alternatives) and nine evaluation criteria under the consultation of an expert in the tooling application and tribological field. To deal with this coating material selection problem, an integrated fuzzy-multi attributed decision-making method is proposed which comprises best worst method and fuzzy-Measurement Alternatives and Ranking according to the Compromise Solution method. This integrated fuzzy- multi attributed decision-making method is used to evaluate the alternatives, and the obtained results were scrutinized via utilizing various sensitivity analysis procedures. In the first phase of analysis, seven scenarios of criteria weight change were used, which was derived by the best-worst method; dynamic matrices are used in the second phase of analysis. In the third and fourth phases, obtained ranks were compared with those obtained by different weight calculation methods and ranking methods, respectively. In the present study, AlCrN/TiAlN coating (alternative Cm5) was found to be the best coating material based on the results obtained after sensitivity analysis. Further, in this study, we have proposed a novel method that helps to solve the coating material selection problem or any kind of selection complications