الفهرس 
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Abstract
Electroless plating has unique properties such as : uniform thickness, high corrosion resistance, and high mechanical properties.
This thesis is focused on studying the electroless plating process of nikle-boron –cobait deposits. The previous studies on the electroless NI-B-CO deposits have not involved the conditions of this study specially the low boron content, the effects of heat treatment and the relatively low temperature degree of bath.
The properties of electroless NI-B and NI-B-CO deposite were also investigated. The studied properties are: microstructure, microhardness, ductyility, wear resistance and corrosion resistance. The variables embodied are plating time and heat treatment temperature.
The effect of changing plating time on the coating thickness behavior of an electroless NI-B and NI-B-CO was alo studied. For as plated samples the X-ray diffraction patterns of NI-B and NI-B-CO alloys, showed that unheated deposits all are microcrystalline. Evidence crystalline of structure was observed for CO&NI and pronounced crystallization and grain growth for NI3B have been noticed for deposits heat treated at 400 c for one hour, also around this temperature maximum microhardness and minimum ductility were achieved.
Heat treatment for one hour at different temperature of electroless NI-B and NI-B-CO coatings showed excellent corrison resistance of NI-B-CO coating compared to NI-B deposits.
The obtained results showed that minimum surface wear and maximum corrosion resistance occurred after heat treatment at 700c.