The lower the hardness of contact material against WC coating, the higher the static friction coefficient of a pair.The roughening WC coating and the smoothin...是什么意思_The lower the hardness of contact material against WC coating, the higher the static friction coefficient of a pair.The roughening WC coating and the smoothin...在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句