单选题
银汞合金的腐蚀主要表现为（ ）。
发布日期：2022-06-28
蠕变
膨胀
失泽
收缩
疏松
试题解析
银汞合金
银汞合金(amalgam)是一种特殊类型的合金，可由汞与一种或多种金属形成。用于牙体修复的汞合金是一种历史悠久的牙科充填材料，我国苏恭著《唐本草》（公元659年）中就有银膏的．记载。李时珍所著的《本草纲目》（公元1578年）对此进行了更加详细的描述。1896年美国C．V．Black对银汞合金的组成、性质、调和及充填方法进行了大量的研究和改进，使银汞合金逐渐成为较理想的充填材料。尽管治疗龋病的充填材料甚多，但后牙的充填，尤其是牙合力较大的洞形还没有比银汞合金更为优越的充填材料。
- 中文名
- 银汞合金
- 领域
- 医疗卫生
- 学科
- 口腔内科
- 外文名
- amalgam
- 专业
- 医学，兽医学
- 相关学科
- 材料科学
腐蚀
腐蚀（ biting）是指涂有腐蚀剂（MORDANT）的金属板被置换到盛有酸的浴器中发生的腐蚀作用。金属腐蚀剂的成分构成、浓度、温度和运用金属板的熟练程度决定了腐蚀过程（即蚀刻线的深度、幅度和均匀度）和板子的耐久性（即经受合理大量复制磨损的承受能力）。蚀刻金属腐蚀剂从所有方向侵蚀并因而造成板面上趋于脆弱的、中空缺口的结构。这时单独或加入硝酸中使用氯化铁（FERRIC CHLORIDE）可以使腐蚀凹槽更加垂直，从而使蚀刻线更好的经受印刷的磨损。当由于一些原因腐蚀剂蚀刻通过或浮雕蚀刻底版（ETCHING GROUND）时，不理想的现象是不良腐蚀（FOUL BITING）的发生，另外一个缺陷是由于过分腐蚀导致在蚀刻板上造成的缺隙（CREV ）。腐蚀的程度不仅取决于腐蚀剂的性能，而且由板子离开酸浴的时间长短所决定。当板子浸入腐蚀剂中一小会儿以后，就可以移开；在板子移开之前，有可能很模糊的线条可以进
- 中文名
- 腐蚀
- 所属学科
- 化学
- 定义
- 涂有腐蚀剂的金属板被置换到盛有酸的浴器中发生的腐蚀作用
- 外文名
- corrode
- 应用领域
- 术语
- 分类
- 氢腐蚀、磨损腐蚀、选择性腐蚀、点蚀、缝隙腐蚀
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