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Chemical reduction process and properties of prepared copper clad iron

Author: MaLiTao
Tutor: ZhuXiaoYun
School: Kunming University of Science and Technology
Course: Materials Science
Keywords: Copper clad iron Coated powder Chemical reduction Passivation Mechanism
CLC: TF123.12
Type: Master's thesis
Year: 2009
Downloads: 56
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Abstract

The coated powder is a new type of coating material and powder metallurgy material its unique properties and many varieties are widely used in the defense industry, machinery manufacturing, chemical industry and other fields. Coated powder at the micro level with multiphase coating integrity, and the characteristics of each component can be highlighted in different needs; having a uniform macroscopic product metallographic structure can be very uniform, and greatly reduce or eliminate the uneven mixing caused by the product composition of different performance unstable ills. This article briefly describes the basic principles of the coated powder electroless copper plating, copper clad iron powder preparation techniques research status, reduced iron powder as raw material, the system appearance in alkaline electroless copper plating system sundby density and other properties of copper clad iron powder. The pre-treatment process, copper plating process, the process of surface modification and copper clad iron performance study, a preliminary analysis of alkaline electroless copper plating deposition mechanism, the following conclusions: 1. Pretreatment process research shows that: before The treatment process is the key to the success of copper plating. Matrix to take a two-step pre-treatment of pickling → caustic washing after copper plating works best. The choice of the complexing agent is alkaline electroless copper plating determinants. Complexing agent D and copper network and better, and ultimately better coated copper clad iron powder. The pH of the bath copper clad iron powder colors and electroless copper plating speed impact paper segmented supplemented with sodium hydroxide amount, so that the pH value of the copper plating system maintained at the copper plating need basic values. Reducing agent concentration, bath temperature, the main salt concentration on the deposition rate and copper clad iron powder color, thereby affecting the bulk density and particle size distribution. Stirring intensity on the performance of the copper-clad iron. 3 to determine the preferred copper process conditions: the concentration of reducing agent, 25ml / L; complexing agent concentration, 100g / L; surfactant concentration of OP-10, 0.03 g / L; main salt, 33g / L; bath temperature, 45 ° C; liquid to solid ratio, 30; mechanical stirring intensity: 300 ~ 500r/min; pH value of 12-13; sodium hydroxide supplemented times 4-5 times. Copper coated iron powder post-passivation process: the BTA and PVP synergy passivation better, the amount of BTA, 6 g / L; surfactant A 4 g / L. Passivation temperature of 50-55 ° C, processing time for 3mmin. Performance copper clad iron: studies have shown that the copper content greater impact of color and grain size of the copper-clad iron and copper clad iron powder bulk density, the bulk density of the copper-clad iron by iron matrix powder. Oxidation resistance test showed that the the theoretical copper content of 20wt% copper clad iron powder room temperature oxidation resistance better; surface morphology observed: the matrix iron powder surface is smooth, showing more obvious granular copper coated crystals, the copper clad iron plating layer is more uniform, and a thickness of about 447nm.

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