Abstract: A rotor for use with a caliper in a brake system of a vehicle. The rotor has a hub with a plurality of openings therein for attachment to an axle which rotates with a wheel of the vehicle. The hub has spokes which radially extend from the hub to an integral annular head member. The head member has parallel first and second friction surfaces thereon for engagement with brake pads on actuation during a brake application. The rotor which is made from a composition consisting essentially of from 50-85 percent by volume of silicon carbide and 50-15 percent by volume of copper and from 0-15 percent by volume of graphite fiber, develops a thermal conductivity at room temperature of from 0.16-0.74 cal/cm.multidot.sec.multidot..degree.C. (50-310 W/m..degree.K.).

Abstract: A brake rotor for use with a caliper in a brake system is made from a composition having from 20-80 percent by volume of silicon carbide and from 80-20 percent by volume of an iron alloy consisting of: 0.4 to 4.0 percent by weight of total carbon; 1.8 to 18.0 percent by weight of Si; 1.0 to 10.0 percent by weight of X where X is selected from a group consisting of Cr, Mo, Mn, Ni, P and S; and the balance of iron alloy being Fe, the composition having a theoretical thermal conductivity at room temperature of 0.19 to 0.41 cal/cm*sec*deg C.

Abstract: A heated resistive type sensor (20) for detecting the oxygen content in an exhaust gas is connected to an electronic control unit (22) for regulating the air/fuel ratio used to operate an internal combustion engine (10). The sensor (20) has a heater (70) which provides a constant thermal energy level to a titania sensing element (76) whose resistance to the flow of electrical current is directly related to the percentage of oxygen in the exhaust gas. The electrical resistance is used as a control signal to maintain the air/fuel ratio within set limits. The resistive portion consists of three resistive elements, one that senses O.sub.2 that is made of titania - TiO.sub.2, the other two resistors are thick film type connected in series thereto. Finally, the gas sensing layer and electrode leads attached thereto are covered by a protective glass layering to prevent contamination of the sensor element.