Pretreatment compositions for metals

A solid composition for use in aqueous solution in the cleaning and conditioning of the surface of a metal selected from the group consisting of iron, zinc, aluminum, and alloys of said metals, prior to the application on said surface of a conversion coating, which solid composition contains in percent by weight:

• (i) a titanium salt in an amount from about 0.01 to about 0.18%, calculated as titanium ion,
• (ii) an alkali metal phosphate selected from the group consisting of mono-, di- and tri-alkali metal orthophosphates and mixtures thereof, in an amount from about 0.6 to about 16%, calculated as PO.sub.4,
• (iii) an alkali metal polyphosphate or pyrophosphate or mixtures of said polyphosphate and pyrophosphate, in an amount from about 3 to about 14.5%, calculated as P.sub.2 O.sub.5,
• (iv) an alkali metal carbonate selected from the group consisting of alkali metal carbonates, bicarbonates, and sesquicarbonates and mixtures thereof, in an amount from about 1.6 to about 37%, calculated as CO.sub.3,
• (v) an alkali metal hydroxide in an amount from about 1.5 to about 11%, calculated as hydroxyl,
• (vi) an alkali metal salt of EDTA in an amount from about 0.3 to about 9.3%, calculated as EDTA.
• (vii) an alkali metal silicate selected from the group consisting of alkali metal metasilicates, alkali metal orthosilicates, and mixtures thereof, in an amount from about 3.5 to about 41%,
• (viii) the anionic surfactant sodium butoxy-ethoxyacetate in an amount from about 1 to about 15%, and
• (ix) a non-ionic surfactant in an amount from about 0.1 to about 7.5%.