聚醚醚酮化学镀镍磷合金镀层及其性能研究报告

聚醚醚酮化学镀镍磷合金镀层及其性能研究随着轻量化的发展，具有高比强度的特种工程塑料聚醚醚酮(PEEK)在国防、航空航天、电子等高科技领域具有广阔的应用。但是，由于PEEK及其复合材料的导电性极差，对电磁波基本没有屏蔽作用，这严重的限制了它作为电磁屏蔽材料的应用。常用的电磁屏蔽材料是具有良好导电性的金属材料，但是由于金属的比重大，不利于轻量化发展。化学镀镍磷是一种常用的聚合物表面金属化技术，它使材料既保持聚合物低比重的特性又拥有金属的良好导电性，是改善聚合物电磁屏蔽性能最有效的方法之一。

本论文为了提高碳纤维增强PEEK的电磁屏蔽性能，使用化学镀方法在碳纤维增强PEEK基体上沉积上一层镍磷合金镀层，通过研究镀液成分配比(主盐、还原剂)及工艺参数(镀液温度、镀液PH、施镀时间)对镀层沉积速率的影响确定了PEEK化学镀镍磷的最佳配比和工艺参数，并对镀层的组织结构、成分、表面形貌进行了分析。为了提高镍磷镀层表面质量，以一种含铜离子化合物为光亮剂，研究分析了光亮剂浓度对镀层组织结构、成分、表面形貌、耐蚀性和电磁屏蔽性能的影响；为了延长镍磷镀层的使用寿命，对镍磷合金镀层进行钝化处理，系统研究了钝化处理对镍磷合金镀层耐蚀性和抗氧化性的影响，通过对比氧化前后钝化与未钝化镍磷镀层的电磁屏蔽性能，分析研究了钝化处理对镍磷合金镀层在自然环境和氧化性环境下电磁屏蔽性能的影响。

1. PEEK化学镀镍磷合金最佳成分配比和工艺参数为：主盐浓度25g/L、还原剂浓度30g/L、PH=6.1、温度80°C、施镀时间1.5h。通过XRD、SEM和EDS分析表明，镍磷镀层与基体有良好的结合，具有良好表面质量，此时镀层是P含量为15.41wt.%的混晶组织。

2. 光亮剂浓度为0.2g/L时，PEEK化学镀镍磷镀层沉积速率最小、镀层的致密度最高、颗粒大小最均匀。EDS和XRD分析表明，镀层中Ni含量随光亮剂浓度的增加逐渐减小，光亮剂浓度小于0.3g/L时，镀层为无铜镍磷非晶；光亮剂浓度大于0.2g/L时，镀层为镍磷非晶与镍铜微晶组成的混晶结构。电化学性能及电磁屏蔽性能测试表明，镀层在光亮剂浓度为0.2g/L时具有最佳的耐蚀性和电磁屏蔽性能。

3. 钝化处理不影响镍磷镀层的组织形貌。XPS分析表明，钝化镍磷镀层含

有Cr元素，且Cr以Cr

2O

3

和Cr(OH)

3

的三价化合物形式存在。电化学性能测试

表面钝化镍磷镀层与未钝化镍磷镀层在3.5wt.%NaCl和16.8wt.% HNO

3

溶液具有

相似的腐蚀机理。但在两种溶液中，钝化镀层的钝化平台更宽、腐蚀电位(E

corr

)

更高、腐蚀电流密度(i

corr )更低、电荷转移电阻(R

ct

)更大，钝化处理显著提高了镍

磷镀层的耐蚀性和抗氧化性能。

4. 16.8wt.% HNO

3

氧化试验进一步证实钝化处理提高了镍磷镀层的抗氧化性能。电磁屏蔽性能测试表明，镍磷镀层具有良好的电磁屏蔽性能。在自然环境中，

钝化处理对镀层屏蔽性能的提高效果不明显。经过16.8wt.% HNO

3

溶液氧化后，钝化后镍磷镀层电磁屏蔽性能的显著高于未钝化镀层。这说明钝化处理能够显著的提高镍磷镀层在氧化性环境下的电磁屏蔽性能。

关键词：

化学镀镍磷，光亮剂，钝化，耐蚀性，电磁屏蔽性能

Abstract

Electroless Ni-P alloy coating on CFs reinforced PEEK and the effect of plating parameters on the properties of coating

Polyether ether ketone (PEEK) is one of the unique thermoplastic engineering materials, which is wildly applied in the area of aerospace, defense, and electronic munication industries. However, the application of PEEK aselectromagnetic interference (EMI) shielding material was limited due to theirlow conductivity.Metallic materials are the best candidates for EMIshielding materials, since they own outstanding conductivity. However, their drawbacks such as heavy densitygo against the trend of lightweight. Electrolessdeposition technique is a wildly used method of surfacemetallization

technique for plastics, which can retain the lightweight feature of plastics and introduce the conductivefeature of materials.

Ni-P alloy coating was electrolessly deposited on PEEK from a bath using a copper-based poundas brightener and the influences of nickel salt concentration, reducing agentconcentration, PH, temperature and deposition time on the deposition rate were investigated to determine the optimum process parameters.Characterization methods including XRD, SEM and EDS were used to investigate the phase structure, morphology and position.The effect of brightener on the coating characteristics, corrosion resistance and EMI shielding effectiveness (SE) was investigated. A passive film was formed on Ni-P alloy coating andthe effects of passivation on the oxidation behavior and EMI SE investigated.

1.The optimum process parameters of electroless Ni-P alloy coating on PEEK are that nickel salt is 25g/L, reducing agent is 30g/L, PH value is 6.1, temperature is 80°C and deposition time is 1.5h. XRD, SEM, EDS observations revealed that the structureof the coating is mixturesof amorphous and microcrystalline,and the coating have dense and uniform nodules with15.41wt.% of P.

2. The deposition rate reached a minimum when the brightener concentration is 0.2g/L. At this concentration, the coating has the most pact and smoothest nodules. EDS study shown that the nickel content of the coatings decreasedsignificantly with the increase of brightener concentration in the plating bath. XRD observation revealed that the structuresof the coatings obtained at brightenerconcentrationunder 0.3g/L are amorphous and structures in the coatings obtained at