【題目】下列關于合金的敘述中正確的是( )

A. 合金是由兩種或多種金屬熔合而成的

B. 日常生活中用到的五角硬幣屬于銅合金

C. 合金在任何情況都比單一金屬性能優(yōu)良

D. 低碳鋼比中碳鋼強度高

【答案】B

【解析】合金是金屬與金屬或金屬與非金屬熔合而成的，A項錯誤；合金的性能一般比單一金屬性能優(yōu)良，但并不是任何情況都是，如純鋁的導電性比鋁合金要好，C項錯誤；含碳量高強度大，中碳鋼比低碳鋼強度高，D項錯誤。

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