The present invention provides an electrorheological fluid, which includes a dielectric particle, a conductor particle and insulating oil, and the dielectric particle is evenly dispersed in the insulating oil; wherein the conductor particle is evenly dispersed in the insulating oil or inlaid in an interior and on a surface of the dielectric particle. The electrorheological fluid has the advantages of high shear stress, long service life, good temperature stability and small leakage current.

Grease wear test device includes a body in a form of a collar having an outer surface, a first side and an opposing second side, which are open to form a hollow, open channel through the body, which has a center axis, into which opposing vee blocks can be inserted; and perpendicular to the center axis, a pair of opposing holes through and open to the outer surface of the body and the cylindrical inside wall, through which a cylindrical test journal (falex pin) can be inserted for contact in general with opposing vee-shaped channels of the inserted, opposing vee blocks, and for rotation during testing. The device can be used to modify a falex pin and vee block device, to receive and contain a small sample of grease or another organic paste product for testing such as a modified version of an ASTM D2670 test method for measuring wear properties of fluid lubricants (falex pin and vee block method).

Grease wear test device includes a body in a form of a collar having an outer surface, a first side and an opposing second side, which are open to form a hollow, open channel through the body, which has a center axis, into which opposing vee blocks can be inserted; and perpendicular to the center axis, a pair of opposing holes through and open to the outer surface of the body and the cylindrical inside wall, through which a cylindrical test journal (falex pin) can be inserted for contact in general with opposing vee-shaped channels of the inserted, opposing vee blocks, and for rotation during testing. The device can be used to modify a falex pin and vee block device, to receive and contain a small sample of grease or another organic paste product for testing such as a modified version of an ASTM D2670 test method for measuring wear properties of fluid lubricants (falex pin and vee block method).