| 摘要 |
PURPOSE:To prevent the creation of a chromium carbide layer and as well to enhance the mechanical strength and durability of a brake disc, by copper-brazing a stainless steel disc to a carbon containing steel base disc annularly nickel-plated. CONSTITUTION:A base disc 34 made of middle or high carbon steels or alloyed steels containing a large amount of carbon, is formed with serveral noches 38 in the outer peripheral part of the disc 34 to be substantially formed in a comb- like shape, and is nickel-plated on the left and right surfaces of the disc 34. A friction plate 36 annularly formed with stainless steels is copper-brazed to the comb-like section of the base disc 34 with the use of a predetermined thickness copper foil which is compressed and heated. A part of notches 38 is opened to the inner diameter section side so that centrifugal ventilation is carried out upon rotation to enhance its cooling capacity. Chromium contained in the friction plate 36 is dissolved into a copper layer 42, and therefore, is precipitated on the outer surface of the nickel-plate layer 40 so that a chromium layer 44 is formed. Carbon contained in the base disc 34 is prevented by the chromium layer from being diffused, and therefore, is not bound with chromium so that no chromium carbide which is fragile is created. Nickel is diffused into the base disc 34 and the copper layer 42 and is alloy therewith so that strong binding may be obtained. |
