alloy

An alloy is an admixture of metals, or a metal combined with one or more other elements. For example, combining the metallic elements gold and copper produces red gold, gold and silver becomes white gold, and silver combined with copper produces sterling silver. Combining iron with non-metallic carbon or silicon produces alloys called steel or silicon steel.

The resulting mixture forms a substance with properties that often differ from those of the pure metals, such as increased strength or hardness. An alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility [延展性], opacity [不透明度], and luster [光泽].

Alloys are used in a wide variety of applications, from the steel alloys, used in everything from buildings to automobiles to surgical tools, to titanium alloys used in the aerospace industry, to beryllium [铍pí]-copper alloys for non-sparking tools. In some cases, a combination of metals may reduce the overall cost of the material while preserving important properties. In other cases, the combination of metals imparts [赋予] synergistic [增效的] properties to the constituent metal elements such as corrosion resistance or mechanical strength. Examples of alloys are steel, solder [焊锡], brass, pewter [白镴là], duralumin [杜拉铝,硬铝], bronze, and amalgams [汞齐].

synergy: the additional effectiveness when two or more companies or people combine and work together

Pewter is a malleable metal alloy consisting of tin (85–99%), antimony [锑tī] (approximately 5–10%), copper (2%), bismuth [铋bì], and sometimes silver. Pewterware are articles [物品] made of pewter.

Duralumin is a trade name for one of the earliest types of age-hardenable aluminium alloys. Its use as a trade name is obsolete, and today the term mainly refers to aluminium–copper alloys, designated as the 2000 series by the International Alloy Designation System (IADS), as with 2014 and 2024 alloys used in airframe fabrication [manufacture].

In addition to aluminium, the main materials in duralumin are copper, manganese [锰] and magnesium [镁]. For instance, Duraluminium 2024 consists of 91-95% aluminium, 3.8-4.9% copper, 0.3-0.9% manganese, 1.2-1.8% magnesium, <0.5% iron, <0.5% silicon, <0.25% zinc, <0.15% titanium [钛].

六级/考研单词: alloy, copper, silver, carbon, silicon, seldom, differ, conduct, opaque, automobile, constituent, corrode, brass, bronze, tin, aluminum, designate, fabricate

"Give us this day our daily bread, on earth as it is in heaven." 和“民以食为天”意思好像差不多。

汞齐即汞合金，齐是合金的意思。用于牙体修复的汞合金是一种历史悠久的牙科充填材料，我国苏恭所著的《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。