Known disks for vehicle brakes are made of cast iron, possibly with additives of various elements such as, for example, silicon and manganese.

A problem which afflicts known cast-iron disks consists of the corrosion to which the disks are subject due to external agents, for example, atmospheric agents.

Corrosion of the disks occurs to a more pronounced extent during periods of prolonged inactivity of the vehicle, for example, during relatively long storage periods when the product is finished, prior to the actual delivery of the vehicle to the final user.

A known solution to this problem consists in coating the brake disks with layers of protective material, for example, layers of special protective oils or other substances such as the commercially-known Dacromet.

However, the protection against corrosion offered by these layers of protective material must necessarily be slight in order not to detract from the efficiency of the braking system of the vehicle on the first occasions on

which it is used, which would be extremely dangerous. The provision of more resistant protective layers would in fact impose on the final vendor the burden of performing a pre-delivery check of the vehicle in order to remove the protective layer from the disks completely and thus to re-establish full efficiency of the braking system.

The protective layers are therefore designed to be removed automatically after a very small number of braking operations.

The protective layers normally used to protect the disks against corrosion consequently have a limited life and, when the vehicle remains stationary for a period longer than that envisaged, their protective effect may disappear and the disks may become subject to corrosion again.

A further problem of known cast-iron disk-brake disks results from the fact that a vehicle may also be faced with prolonged periods of inactivity in the course of its life, after delivery to the final user. During these periods, the brake pads may bind to the surfaces of the respective disks. This causes mutual contamination or tainting of the pads and of the disks owing to migration of substances of which they are composed in both directions.

The contamination is localized at a particular point

on the disk and this gives rise to vibrations during braking when the vehicle returns to use.

In view of the prior art described, an object of the present invention is to provide a material for vehicle brake components, particularly but not exclusively for disk-brake disks, which is not afflicted by the problems exhibited by the prior art.

According to the present invention, this object is achieved by means of a cast-iron for vehicle brake components, particularly disk-brake disks, characterized in that it includes a quantity less than or equal to lot by weight of aluminium.

The characteristics and the advantages of the present invention will become clearer from the following detailed description of some practical embodiments, provided purely by way of absolutely non-limiting examples.

Example 1 Foliated gray iron: Aluminium: from 4.0% to 7.0% by weight, preferably 5.0%; Carbon: from 3.1% to 3.5% by weight, preferably 3.3%; Silicon: from 1.8% to 2.2% by weight, preferably 2.0%; Manganese: from 0.5% to 0.8% by weight, preferably 0.65%; Iron: from 90.6% to 86.5% by weight, preferably

89.05%; Example 2 Copper and chromium gray iron with a high carbon content: Aluminium: from 4.0% to 7.0% by weight, preferably 5.0%; Carbon: from 3.55% to 3.85% by weight, preferably 3.7%; Silicon: from 1.6% to 2.1% by weight, preferably 1.85%; Manganese: from 0.4% to 0.8% by weight, preferably 0.6%; Chromium: from 0.1% to 0.3% by weight, preferably 0.2%; Copper: from 0.3% to 0.6% by weight, preferably 0.45%; Iron: from 90.05% to 85.35% by weight, pref. 88.2%; Example 3 Foliated gray iron: Aluminium: from 1.6% to 3.9% by weight, preferably 3.0%; Carbon: from 3.1% to 3.5% by weight, preferably 3.3%; Silicon: from 1.8% to 2.2% by weight, preferably 2.0%; Manganese: from 0.5% to 0.8% by weight, preferably 0.65%; Iron: from 93.0% to 89.6% by weight, pref. 91.05%; Example 4 Copper and chromium gray iron with a high carbon content:

Aluminium: from 1.6% to 3.9% by weight, preferably 3.0%; Carbon: from 3.55% to 3.85% by weight, preferably 3.7%; Silicon: from 1.6% to 2.1% by weight, preferably 1.85%; Manganese: from 0.4% to 0.8% by weight, preferably 0.6%; Chromium: from 0.1% to 0.3% by weight, preferably 0.2%; Copper: from 0.3% to 0.6% by weight, preferably 0.45%; Iron: from 92.45% to 88.45% by weight, pref. 90.2%.

If a cast iron according to the present invention is used for the manufacture of disk-brake disks, it solves the problems of corrosion of the disks during periods of inactivity of the vehicles prior to delivery to the final users and of contamination or tainting of the disks and of the pads which may occur in the event of more or less prolonged periods of inactivity of the vehicles, thus eliminating vibrations during braking to which this contamination leads when the vehicles return to use. The addition of aluminium to the conventional composition of the cast iron does not adversely affect the other characteristics of the material; on the contrary, with the particular quantity of aluminium according to the invention, the cast iron has an acceptable hardness and is even more wear resistant.

Although the examples described relate to two

particular types of cast iron, clearly the invention is applicable, in general, to cast iron of all types.

Although the examples given above are advantageously applicable to the production of disk-brake disks, they may, however, also be used for the production of other vehicle brake components.