Hydroxyapatite composite coatings were classified into three kinds according to their feature, i. e. single layer composite coating, double layer composite coating and gradient composite coating.

将羟基磷灰石复合涂层按照特征分为三类，即单层复合涂层、双层复合涂层和梯度复合涂层。

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The gradient PPS/FEP composite anti-corrosive coatings were prepared on carbon steel. The bonding strength of all coating systems was determined by the pull-off test.

在碳钢表面制备了具有梯度结构的PPS/FEP复合防腐蚀涂层，采用拉开法测定了各涂层体系的结合强度。

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