Título

DESENVOLVIMENTO DE UM PARÂMETRO DE SEVERIDADE GLOBAL PARA O ESTUDO DO DESGASTE DE TERMOPLÁSTICOS

DEVELOPMENT OF GLOBAL SEVERITY PARAMETER FOR WEAR STUDY OF THERMOPLASTICS

Autoria

Silva, Carlos Henrique da; Sinatora, Amilton

DOI

10.5151/2594-5327-0436

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Resumo

O presente trabalho tem como objetivo estudar o efeito da carga normal aplicada, da velocidade de deslizamento, do acabamento superficial e do tipo de contra-corpo, no comportamento tribológico dos materiais poliméricos POM e UHMWPE. Foram realizados ensaios de desgaste em um tribômetro do tipo pino-contra-disco, com os pinos de materiais poliméricos e os discos de alumina e aço inoxidável. Nestes ensaios utilizou-se 3 valores de carga, 3 velocidades de deslizamento e 3 níveis de acabamento superficial do contra-corpo. Para cada condição foram realizados 3 ensaios. Durante os ensaios, foram monitoradas a temperatura próxima à interface dos materiais, a força de atrito e o deslocamento vertical do pino, o qual foi utilizado para a determinação da taxa de desgaste do polímero. A distância percorrida foi de 3.500 metros e os ensaios foram realizados em ambiente com umidade relativa controlada em 50

 

The present work has as objective to study the effect of the applied normal load, the sliding velocity, the roughness and the type of counter-face, in the wear behavior of polymeric materials: POM and UHMWPE. Was used a pin-on-disc tribometer, with the polymeric pins and alumina and duplex stainless steel discs. In these tests were used 3 values of load, 3 sliding velocity and 3 level of surface finishing of counter-face. For each test conditions 3 assays had been carried through. During the tests, was monitored the temperature near of the contact, friction force and the vertical displacement of the pin, which was used for determines the wear rate of polymers. The covered distance was of 3.500 meters and the tests had been carried through in environment with controlled relative humidity in 50 ± 5 %. To analyze the wear behavior was proposed a global severity parameter (PVR/DD). Was considered mechanical factors (PV values), a topographic factor (roughness of counter-face, R) and a thermal factor (thermal diffusivity of the materials in contact, DD). It was observed that the vertical pin displacement not occurs only due to the wear, but too the polymer creep. The wear results were organized in the form of wear maps that considered three phenomena: creep, wear and melting. Was observed that the more important parameter of the tribosystem is the capacity of heat dissipation from the contact region.

Palavras-chave

Tribologia; Mapas de desgaste; Polímeros; Fluência.

Tribology; Wear maps; Polymer; Creep.