The phase diagram of the system formed by diethanol ammonium dodecanoate ( DCD ) / n-butano1 / paraffin oil (LP) /water was determined The lyotropic liquid crystal region was confirmed and the use of liquid crystal as lubricant on aluminum alloy surfaces was studied. The effect of the liquid crystal structure on the tribological properties was also evaluated. Comparing the wear scar widths and the vertical loads of liquid crystal with that of a commercial grease. The lamellar liquid crystal showed a higher load carrying capacity relative to the commercial grease.