Tribological Properties Of Laser Textured Surfaces Of Ti6Al4V

Tribological characteristics of Titanium alloy can be improved significantly by surface modification treatment. In this thesis, line texture, grid texture and dot texture were prepared on titanium alloy surface by laser surface modification technique. The characterization to various textured surfaces was conducted. The relationships between friction coefficients and spacing of texture, load and sliding velocity were analyzed. The comparation on textured surfaces and polished surface was done by wear track analysis. Main results were concluded as follow.1. The regular line texture, grid texture and dot texture are formed after laser textured surface treatment, and the hardness of various specimens increases significantly. The specimens with dot texture possess the highest hardness, the specimens with grid texture are in the second, and the hardness of specimens with line texture is the lowest. In the same spacing, the roughness of specimens with grid texture is the largest, and that of specimens with line texture takes second place. The roughness of dot texture is the lowest.2. The friction coefficients of specimens with dot texture are smaller than that of polished specimens in the condition of high load and large spacing. Higher load and larger spacing help to reduce friction coefficient. The friction coefficients of specimens with grid and line texture are larger than that of polished specimens, and the friction coefficients of specimens with grid texture are larger than that of specimens with line texture, which means that not all textured surfaces can reduce friction coefficients. On the contrary, friction coefficients increase when the effect of friction drag increasing by groove or dot in textured surface is stronger than that of debris capturing and ploughing or cutting reduction.3. Friction coefficients become steady for textured surfaces in high sliding velocities. Friction coefficients become unsteady for textured surfaces with load increasing. The effect of spacing of line texture on friction coefficients possesses no clear regularity. Friction coefficients become smaller with spacing of grid texture increasing. Smaller friction coefficients appear for larger spacing of dot texture.4. The wear on polished surfaces is very serious and wear tracks are deep with a great deal of debris, which means ploughing action and adhesive wear. Wear tracks are not very deep and the surface structures are intact, which indicates that wear is not so serious as polished surfaces. The antiwear resistance for dot textured specimens increase significantly because of theirs capturing debris action of dots.