Análise Comportamental Dos Coeficientes De Atrito E Desgaste De Sistemas Revestidos Submetidos a Desgaste Micro-Abrasivo

Abstract

ResumoEste trabalho objetiva estudar a influência das durezas de filmes finos de nitreto de titânio (TiN) e carbeto de titânio (TiC) sobre os coeficientes de atrito e desgaste, em ensaios ball-cratering. Uma esfera de aço AISI 52100 e dois corpos de prova de aço-ferramenta AISI D2, um revestido com TiN e outro revestido com TiC, foram utilizados nos experimentos. A pasta abrasiva foi preparada com partículas de carbeto de silício (SiC) preto e água destilada. Duas forças normais e seis distâncias de deslizamento foram definidas, sendo as forças normal (N) e tangencial (T) monitoradas constantemente. Assim como N e T, com o auxílio de uma Régua Linear, o deslocamento (h) do corpo de prova, na direção paralela à aplicação da carga normal, foi continuamente medido, o que permite o cálculo do coeficiente de desgaste para as diferentes distâncias de deslizamento sem a necessidade de interrupção do ensaio. O coeficiente de atrito é determinado pela relação entre as forças tangencial e normal e, para ambos os revestimentos, os valores permaneceram, aproximadamente, na mesma faixa (entre µ = 0,4 e µ = 0,9). Por outro lado, o coeficiente de desgaste diminui com o aumento da dureza do revestimento. Palavras-chave: Ensaio de desgaste; Coeficiente de atrito; Coeficiente de desgaste. ANALYSIS OF THE FRICTION AND WEAR COEFFICIENTS OF COATED SYSTEMS SUBMITTED TO MICRO-SCALE ABRASION AbstractThis work aims to study the influence of titanium nitride (TiN) and titanium carbide (TiC) coatings hardness on the friction coefficient and wear coefficient in ball-cratering micro-abrasive wear tests. A ball of AISI 52100 steel and two specimens of AISI D2 tool steel, one coated with TiN and another coated with TiC, were used in the experiments. The abrasive slurry was prepared with black silicon carbide (SiC) particles and distilled water. Two normal forces and six sliding distances were defined, and both normal (N) and tangential (T) forces were monitored constantly. The movement of the specimen in the direction parallel to the applied force was also constantly monitored with the help of a Linear Ruler. This procedure allows the calculation of the wear coefficient for the different sliding distances without the need to stop the test. The friction coefficient is determined by the ratio between the tangential and the normal forces, and for both TiN and TiC coatings, the values remained, approximately, in the same range (from µ = 0.4 to µ = 0.9). On the other hand, the wear coefficient decreases with the increase in coating hardness.

Micro Abrasive Wear Behaviour Study of Carburization and Ion Plasma Nitriding of P20 Steel

“…In microabrasive wear, the wear mode can occur by scratching, rolling or a combination of both 19 . The wear rolling occurs when abrasives roll over the wear surface, while the wear scratching occurs when the abrasives sliding over the wear surface 19,20 .…”

Determination of the wear resistance of 1020 steel superficially treated in contact with 3104 aluminum alloy using the microwear test compared to the designed wear test evaluated by the moiré optical technique

“…Thus, this test is adequate to determine the wear resistance of thin films and other coats or layers produced by the surface engineering, and, by enabling a wide adjusted range of load, the fixed ball test system is widely used to study the microwear in a variety of materials [29,30]. In this case, the wear resistance is obtained by the crater analysis formed in the test, being possible to determine the wear mechanism, wear volume, wear rate, and the depth of the crater penetration, to verify if the test reaches the substrate during the test or remains on the treated surface [24,[30][31][32][33][34].…”