Determination of wear resistance of thin coated cutting tools by PVD method using micro-scale abrasion test

In this study, it is aimed to increase wear resistance and service life of cutting tools which are frequently used in daily life and industry. The abrasion behavior of powder metal cemented carbide (WC - % 6 Co) a cutting tool material coated with TiN, AlCrN, AlTiN powders, was investigated by micro scale wear test. Coatings of the samples were made by PVD coating method. All coatings have a dense and homogeneous microstructure without delamination or crack formation. Micro abrasion test was applied as abrasion test. Abrasion tests were carried out by micro ball abrasion test method. AISI 52100 (100Cr6) bearing steel with a diameter of 1" (25.4 milimeter) was used as the ball. In this micro ball abrasion test method, fixed ball moves on the sample under certain loads. In the abrasion test, Al2O3 abrasive solution of 800 mesh, 1000 mesh, 1200 mesh was used as abrasive. The abrasive solution was prepared as % 40 Al2O3 and % 60 pure water. The abrasion load was used as 1, 2 and 3N loads and these abrasion tests were applied at 420 rpm and 700 rpm. By measuring the circular cross-section formed by the balls on the sample under SEM and optical microscope, the volume losses were calculated using the obtained values and certain equations and the abrasion resistance of the sample was determined. As a result of the experiments, the samples were first examined under optical microscope and the diameters of the formed craters were measured. The samples were then reduced to appropriate sizes and subjected to SEM analysis. Volume calculations of craters whose dimensions were measured in micro meters were made under optical microscope. According to the volume loss calculations, the most worn specimen was cemented carbide (WC) substrate without coating and the most resistant specimen was AlCrN with the highest hardness. As a result of abrasion tests, abrasion resistance increased in parallel with abrasive particle size, abrasion load, increasing number of cycles and hardness increase.