Preparation Of Metal Cladding Ceramic Composite Powder By Electroless Plating And Its Properties And Applications

Composite material is one of the most important materials in the development of materials science and engineering. It is composed of matrix component and reinforcement component. Properties of each material component are mixed and the comprehensive performance of the composite is developed. In this research, metal cladding ceramic composite powder was prepared by low temperature electroless plating with ultrasonic wave reinforcement. The morphology, composition and bonding state of the composite powder were researched. The composite powder was used as coating material to prepare the laser cladding coating at 45^# steel matrix. The microstructure, properties and interfacial bond strength of the coating were investigated. Meanwhile the composite powder was used to prepare the aluminate spinel. The morphology and properties of the aluminate were studied.By the low temperature electroless plating with ultrasonic wave reinforcement, WC-Co and Al₂O₃-Co composite powder were prepared. EDX was employed to obtain the composition of the composite powder. The morphology of the composite powder was observed by TEM. The content of Co was 16.65At% in WC-Co and 5.26At% in Al₂O₃-Co respectively. The composite powder was homogeneous, dispersive and smooth.The WC-Co composite powder was applied in preparing the laser cladding coating. 45^# steel was used as matrix. The process was performed by TJ-HL-T5000 CO₂ laser device. The morphology of the coating was observed by stereoscopic microscope. OM and SEM were used to research the microstructure and interfacial bond strength of the coating. The optimal laser cladding processing parameters are: laser power 2.4 kw,scanning speed 4.1 m/min and spot size 3 mm. The coating binds with the matrix metallurgically. The micro-hardness was measured of 1196.4 HV_0.1, and the wear resistance was investigated, showing excellent wear resistance.The Al₂O₃-CO composite powder was applied in preparing aluminate spinel. As comparison, CoAl₂O₄ powder was prepared by sol-gel processing. Various characterization techniques were used to secure the properties of the cobalt aluminate spinel prepared by the two different methods. XRD was performed to determine the crystalline phases of the product. The morphology of the CoAl₂O₄ powder and elemental distribution were determined using SEM and EDX, respectively. The temperature of CoAl₂O₄ phase transformation was obtained by differential thermal analysis. The result indicates the CoAl₂O₄ powder prepared by electroless plating was smaller, smoother and more homogeneous. The specific surface was higher than that prepared by sol-gel processing.