Fabrication And Tribological Behavior Of Alumina Based Ceramics With Surface Textures

The design idea of textured ceramics is proposed in this paper,continuous and discrete textures with varying densities has been fabricated on two kinds of alumina based ceramics by utilizing the laser technology.The tribology behavior has been investigated systematically.The effect of different morphology on the friction properties of the ceramics has been analyzed and the wear mechanism has been revealed.Surface textures are fabricated by utilizing the laser technology and the effect of processing parameters such as the scanning power,scanning speed,scanning frequency and scanning times on the texture morphology and the surface quality has been studied.Optimized parameters have been obtained:scanning power of 10 W,scanning speed of 100 mm/s,scanning speed of 50 kHz,scanning times of 1 time.The width of the texture is 30 μm as the depth is nearly the same.Continuous texture array and discrete texture array with varying densities from 5%to 40%have been fabricated with optimized processing parameters on the two kinds of alumina based ceramic samples.The friction properties of the textured alumina based ceramics has been investigated by utilizing the multifunction friction test equipment.Results show that all textured samples can decrease the friction coefficient under dry sliding condition while it is remarkably affected by the texture densities.Lubrication can be a promotion to the antifriction performance which leads to at least 50%friction coefficient off on all tests.Texture morphology can be a key factor that affects the friction properties while continuous textures seem to have a better antifriction performance than discrete ones fabricated on the samples of the same material.Experiment conditions can also be an element that influences the friction properties as continuous textures exhibit a better antifriction performance under moderate load conditions while the discrete ones perform well under heavy load conditions.The friction properties seem to have no significant influence with sliding speeds.The wear morphology and micro-constitution are studied with White Light Interferometer and SEM and the wear mechanism of the textured samples are analyzed.It indicates that there are two effects of textures under dry sliding conditions including aggravating the wear volume of the friction ball and collecting the wear debris.As the density of the textures increases,the two effects exhibit a dynamic balancing process:Much too high or low densities tend to cause an adhesion of the debris on the ceramic matrix while the moderate densities can reduce or even merge that phenomenon.The dominating types of the wear forms on the textured samples can be classified as adhesion abrasion,fatigue wear and abrasive wear under dry sliding conditions while the textures play a role of chamber to collect the lubrication to improve the contact status of the friction pairs and promote the wear resistance of the textured samples observably.