Experimental Investigation of Wear Analysis on TiAlN and AlCrN PVD Coatings (original) (raw)
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Coatings
The TiAlCrSiYN-based family of PVD (physical vapor deposition) hard coatings was specially designed for extreme conditions involving the dry ultra-performance machining of hardened tool steels. However, there is a strong potential for further advances in the wear performance of the coatings through improvements in their architecture. A few different coating architectures (monolayer, multilayer, bi-multilayer, bi-multilayer with increased number of alternating nano-layers) were studied in relation to cutting-tool life. Comprehensive characterization of the structure and properties of the coatings has been performed using XRD, SEM, TEM, micro-mechanical studies and tool-life evaluation. The wear performance was then related to the ability of the coating layer to exhibit minimal surface damage under operation, which is directly associated with the various micro-mechanical characteristics (such as hardness, elastic modulus and related characteristics; nano-impact; scratch test-based characteristics). The results presented exhibited that a substantial increase in tool life as well as improvement of the mechanical properties could be achieved through the architectural development of the coatings.
Wear performance of PVD coated tool steels
Estonian Journal of Engineering, 2012
The paper describes the performance of high alloy tool steels coated by PVD techniques. Performance evaluation was based on the wear resistance in the conditions of prevalence of adhesion and on tool wear (durability) in the conditions of blanking of electrotechnical sheet steel. Hardmetal (WC-15% Co) was used as a primary standard material. It is shown that adhesive wear resistance depends both on the composition of the PVD coating and on that of the tool material to be coated -steels with higher adhesive wear resistance ensure also a higher strengthening effect of the surface. Sharpening of specimens (cutting tools) -removal of coating at the face zone of the tool by grinding -revealed the difference in the efficiency of the coating in different zones of the tool. In terms of durability, thin PVD coatings do not enable improvement of the performance of sheet metal blanking tools (dies, punches). No correlation between durability in blanking and adhesive wear resistance was revealed. In terms of durability prognostication, alloys' (tool steels, hardmetals, cermets) adhesive wear resistance enables tool life assessment only when materials of similar nature (steels, carbide composites) are compared.
Wear on tool steel AISI M2, D6 and 52100 coated with Al 2O 3 by the MOCVD process
Journal of Materials Processing Technology, 2006
Present work investigates the wear resistance of tool steels and 52100 steel coated with Al 2 O 3 by MOCVD process. The wear tests by sliding and abrasion were performed in a pin-on-disk and ball-on-disk apparatus whose pin and ball substrates were steels fabricated from AISI M2, D6 and 52100. The MOCVD coating processes were carried out in a research laboratory apparatus at 200 • C under N 2 + O 2 atmosphere. The counterface disks were ABNT 1008 steel sheet used in the brazilian fridge industry. The wear resistances of the coated tool steels were evaluated trough the pin-on-disk test, using a sliding velocity 0.6 m/s, normal loads of 20 and 30 N, total sliding distance of 2400 m and controlled conditions of temperature and humidity. The pin and ball material substrate were quenched and tempered, and the disks were tested as received. From the plotted graphs of lost volume versus sliding distance, it was observed that occurred a greater wear rate of AISI D6 pins without coating, this is possibly due to more severe adhesion and delamination mechanisms. The AISI M2 and D6 pin coated with Al 2 O 3 showed similar wear resistance and higher resistance than the uncoated D6 pin. However, the tested sphere of AISI 52100 showed different behaviour under 20 N normal load. For both sphere coated with Al 2 O 3 and uncoated the wear rate were similar. From microscopy observations, in order to have accurate measures of ball wear rate, it is proposed a new method to measure wear resistance of ball and pin in the pin-on-disk tests: wear can be measured by the wear track width or area left on the ball tip. The graphs of track width versus sliding distance are shown and the curves for tested material and coating are compared. Pin and ball lower lost volume rate and wear track width with sliding distance is related to greater surface hardness after heat treatment and the coating process. Nitrided M2 and D6 tool steels coated with Al 2 O 3 showed superior wear resistance characteristics for cold working tooling. The spheres of AISI 52100 coated with Al 2 O 3 presented poor wear resistance due to surface defects.
Surface and Sliding Wear Behaviour of Different Coatings and Steels
Ingeniería, investigación y tecnología, 2012
In this work, the sliding wear behaviour of the coatings TiN, CrN and WC/C applied on steel substrates was studied using a reciprocating wear test machine. All tests were carried out in dry conditions, at room temperature (20-23°C and 45%−50% relative humidity). The average sliding velocity was 0.08 m/s and an amplitude of 2 mm was used. The applied loads were 11.76 N (Po = 1.74 GPa) and 7.84 N (Po = 1.52 GPa). Optical microscopy was used to observe the characteristics of wear scars and spalls and possible causes of their formation. The variation of the friction coeffi cient against the number of cycles was obtained. This was used to determine more precisely the time (number of cycles) where the coating presented the fi rst signs of wear, in addition Energy Dispersive X-ray analysis (EDS) was performed, as well as Scanning Electron Microscopy (SEM) and hardness tests on the wear traces, which reinforced the previous observations. Thus it was possible to know the wear life of diff erent coatings and possible causes of variation. Increasing the load was an important factor in the variation of wear life results. But it is also important to consider other factors such as surface roughness and thickness of coatings. keywords • coating • wear • substrate • SEM Surface and Sliding Wear Behaviour of Different Coatings and Steels
Abrasive wear behaviour of nano-TiN coated AISI D3 tool steel
European Mechanical Science, 2022
In this study, the effect of nano-TiN layer obtained by PVD method on tribological behaviour of X210Cr12 (1.2080, AISI D3) cold work tool steel was investigated. Coating process was carried out by cathodic-arc PVD method using 200 V voltage, 350 °C temperature, 4x10-4 mbar pressure, and 50 A current application conditions. The characterization of the coating was carried out by FESEM and SEM-EDS analysis. The coated and uncoated samples were subjected to abrasive wear test against to 220 mesh sandpaper under 3 different loads (5, 10, and 20 N). The tests were applied at three different sliding distances (100 m, 200 m, and 600 m) keeping the sliding speed as constant at 2,6 m/s. For uncoated samples, while the applied load increased from 5 N to 20 N, the approximate wear loss increased by 10 and 8.5 times, respectively. The approximate wear loss increased by 2.2 and 12.2 times, respectively in nano-TiN coated samples. When compared to the coated and uncoated samples, the wear loss values obtained in the coated samples at sliding distances of 100 m and 200 m differed greatly from uncoated samples, under same conditions almost 100%. However, when the sliding distance reached 600 m, the gap started to close and the gap decreased to 30%. Under the same conditions, the wear rate of the coated samples decreased up to 15 times compared to uncoated samples.
2018
The present paper reports the influence of working pressure and nitrogen flow rate on the mechanical and wear properties of TiN thin films deposited by DC reactive magnetron sputtering with RF bias voltage. The process of PVD coating is conducted in a nitrogen-argon gaseous mixture at a temperature of 150°C and a DC power of 200W for 90 min. The micro hardness and the wear resistance of the TiN are determined prior to and after the PVD coating. The wear volumes of samples were evaluated using optical profilometre. Worn surfaces were observed using scanning electron microscopy. It was observed that coated samples showed considerable higher mechanical properties and wear resistance compare to uncoated samples. Abrasive wear mechanism was observed on the surface of worn surfaces.
Wear Mechanism and Tool Performance of TiAlN Coated During Machining of AISI410 Steel
TiAlN films were deposited on a high-speed steel (HSS) tool by a physical vapor deposition technique. This study describes the deposition, characterization and coating phase composition of the composite coating. Dry turning tests were carried out on martensitic stainless steel AISI410 with three series of cutting speed: 30, 120 and 180 m/min, while the depth of cut and feed rate were kept constant at 1 mm and 0.15 mm/rev, respectively. The machined work piece surface roughness, adhesive strength and cutting force of the coated cutting tool were studied. The wear rate and worn surface of the cutting tools were also studied with scanning electron microscopy. The test results show that the cutting performance of the HSS cutting tool was improved with the covering of the TiAlN coating with at least two times increase of cutting life.
Effect of mechanical pre-treatments in the behaviour of nanostructured PVD-coated tools in turning
The International Journal of Advanced Manufacturing Technology, 2014
As a consequence of the lack of characterization of advanced physical vapour deposition (PVD) coatings in the scope of turning, a methodology is presented to evaluate the performance of nanostructured coated tools in the scope of difficult to machine materials turning in particular are austenitic stainless steels. A main aspect of this research is the evaluation of different mechanical pre-treatments before PVD coating in cutting tools. In a first stage, four advanced PVD coatings were analyzed prior to studying the effect of pre-treatments. This stage allowed to identify the nanostructured AlTiSiN coating, commercial denomination nACo, as the one with the best performance for turning austenitic stainless steel. Once the best coating is identified in a second stage, the influence of drag-grinding and microblasting mechanical substrate pre-treatments was analyzed with regard to the performance of coated tools. Several aspects were considered: geometric modification of cutting edge, coating adhesion, substrate roughness and machining performance. The performance of the mentioned coatings was evaluated through wear tests. The machined material was AISI 304L and machining operation was cylindrical turning.
2019
Hard coatings are usually applied to improve high speed steel (HSS) tools performance. However, to achieve this aim, a good adhesion between coating film and substrate is necessary. The coating failure, associated to the lack of adhesion to the substrate, can lead to tool premature wear, reducing its efficiency. The surface modification can improve the coating film adhesion levels by modifying substrates surface roughness, and then, ensuring better anchorage of the deposited layer. In this research two techniques of superficial modification, planar sputtering and chemical polishing, were compared. The sputtering uses plasma application, where cations formed in the reactor collide with samples surface, removing material from it. For chemical polishing, it was used acid and alkaline solutions. After surface treatments, all roughness levels were measured using a roughness tester. The Cathodic Cage Plasma Nitriding (CCPN) technique was used to deposit a TiN film on tools surface. Then, X-ray diffraction, Vickers microhardness and SEM tests were carried out to verify the presence of deposited film, as well as its thickness and mechanical properties, and then, machining tests with SAE 1045 steel where performed, applying the coated tools. Optical microscopy was carried out to track average flank wear up to 0.3 mm, characterizing the end of tool life. It can be observed that all the coated tools obtained an increase in its life, registering the variances according to the different roughness profiles. The best results were verified for chemical polishing with acid solution treatment condition, as it allowed longer machining time with less flank wear.
Journal of Materials Processing Technology, 2005
The paper presents results of the investigation of the structure, mechanical properties and tribological tests of CrN, TiN, TiN/(Ti,Al)N PVD coatings deposited onto X37CrMoV5-1 type hot work steel. Thin hard coatings are today employed in vast number of applications for reducing friction and wear of tools and mechanical components, however there are still big interest to improve tools used in hot-working process e.g. metal die casting, hot extrusion and hot forging as well as glass and plastics processing. The goal of this investigation is to determine usefulness of that coatings type deposition in order to improve wear resistance of tools made from hot work steels. Based on the results of metallographic examinations of microstructure it was shown that TiN, TiN/(Ti,Al)N coatings have compacted, columnar structure while CrN coating has compacted submicrocrystalline structure. According to the observations made after scratch test we found the highest adhesion for CrN monolayer coating and the lowest one for multilayers TiN/(Ti,Al)N coating. Moreover it was found that failure mechanism during scratch test in all investigated coatings begins with multiple spallings located on the scratch edges followed by cracking and total delamination of coating. The wear resistance was investigated by pin-on-disc method performed in room and elevated to 500 • C temperatures. We found that the lowest wear at certain conditions in both room and elevated temperatures shows TiN monolayer coating what can be connected with their good adherence to the substrate materials as well as the highest hardness.