Conversion coating and method of making

A composite comprising:

• a substrate comprising a metal backing underlying a metal surface comprising zinc;
• and
• a conversion coating overlying the substrate and comprising at least one of a zirconium oxide, a hafnium oxide, or a combination thereof;
• the composite exhibiting a corrosion resistance Rt of at least 3000 Ω·cm2, measured at 0.01 Hz;
• and
• the composite exhibiting a peel strength of at least 140 N, the conversion coating formed from a zirconia or hafnia-based complex obtained by reacting a zirconium ion source, a hafnium ion source, or a combination there, with a first chelating compound in a first react and a second chelating compound in a subsequent second reaction wherein at least one of the first and second chelating compounds includes at least one of an ethylene diamine, N,N,N′,N′-tetrakis(2-hydroxypropyl)ethylene diamine, a glycinate, an aspartic acid, an aminopolycarboxylate nicotianamine, an amino acid glycine, a 1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid (BAPTA), a 1,4,7,10-tetraazacyclodecane-1,4,7,10-tetraacetic acid (DOTA), an ethylene glycol-bis(β-aminoethyl ether)-N,N,N′,N′-tetraacetic acid (EGTA), a nitrilotriacetic acid (NTA), an iminodiacetic acid (IDA), or a diethylenetriaminepentaacetic acid (DTPA).