Most metal materials are actually alloys, please give a few examples from your life

For example, the most commonly used stainless steel 1Cr18Ni9Ti

Bronzes are ordinary bronze, i.e., copper-tin alloys.

Brass is a copper-zinc alloy.

Now the doors and windows are made of aluminum alloy.

Steel, brass, aluminum alloy ......Many, much more.

As for the basis for judgment, it seems that there is really nothing other than chemical analysis.

Because pure metal always has a lot of shortcomings, such as aluminum, iron, etc., the strength and hardness of pure metal are very low, and it is not suitable for cooperative components. Some metals such as chromium, nickel, titanium, tungsten and the like are either too hard or very scarce, in addition to insufficient mechanical properties, the price is also very expensive.

However, after these materials are alloyed in a certain proportion, good mechanical properties and suitable costs can be obtained, so general metal materials are alloy products.

Because the properties of pure metal materials are not very good, and they are not easy to smelt. These pure materials are added to some rare metals or other metals to form alloys, and their properties are greatly improved, with good strength, toughness, ductility, heat resistance and many other advantages.

Let's take a look at our pre-work...

(1) Conductivity, ductility, etc. can be answered a point.

2) Compare the hardness of brass (or alloy) and copper (or pure metal) (3) The properties of the alloy are different from the pure metals that compose it (or the melting point of the alloy is lower than that of the pure metals that compose it).

1) It can be used as a wire, indicating that the metal has good conductivity; It can be extended into a wire, indicating that the metal has good ductility. (2) The purpose of the two metal materials being carved against each other is to compare the hardness of the two.

3) According to the order of heating and melting of these three metal materials, the melting point of the alloy is lower than that of pure metal, and the performance is better.

1) Conductivity, ductility, ductility, etc.

2) Compare the hardness of brass (or alloy) and copper (or pure metal).

3）fe2o3

3co<>

2fe＋3co2

Pure metals are not as hard as alloys, and they are susceptible to corrosion and oxidation.

Pure metals are rare, and the properties of pure metals often do not meet our requirements, so except for some special places, we use alloys in other places.

Pig iron, wrought iron, and steel are all alloys of iron and carbon, taking the most common iron as an example. The addition of carbon greatly increases the hardness of iron, allowing iron to have more uses. Another example is aluminum, pure aluminum is very soft, and the hardness will be greatly increased when other metals are added to make alloys.

Of course, pure metals will also be used in some places, such as pure metals will be used as much as possible for wires, which is only part of the use of metals, so the metal we usually use the most is alloy materials.

(1) From the comparison in the table, it can be concluded that the melting point of the alloy is lower than the melting point of its constituent components, and the hardness, strength and corrosion resistance are stronger than those of its component metals, so the answer to this question is: lower melting point, higher hardness and better corrosion resistance;

2) Duralumin contains aluminum, copper and magnesium, which are placed in sufficient hydrochloric acid, and the metallicity of aluminum and magnesium reacts with acid before hydrogen, and copper cannot react with acid after hydrogen; Therefore, the answer to this question is: copper, mg+2HCl, mgcl2+h2

3) Rust conditions of metal iron: iron will rust when it comes into contact with oxygen and water at the same time; Stainless steel is formed, which changes the composition and structure of the metal;

4) a. In the order of metal activity, because the metal aluminum is before the iron and the copper is after the iron, the aluminum can react with the ferrous sulfate solution, and a layer of silvery-white substance is generated on the surface of the aluminum, while the copper cannot react with the ferrous sulfate solution, thus proving the activity order of the three metals: zinc, iron, copper, so a is correct;

b. Since iron and copper are behind aluminum in the order of metal activity, neither copper nor iron can react with aluminum sulfate solution, which can only prove that aluminum is more active than copper and iron, but cannot compare the activity of iron and copper, so B is wrong;

c. Since aluminum and iron are in front of copper in the order of metal activity, copper and ferrous sulfate solution and zinc sulfate solution cannot react, so the activity of copper can only be proved to be weaker than that of iron and aluminum, but it cannot prove the activity of iron and aluminum, so C is wrong;

d. Because in the order of metal activity, iron and aluminum are in front of hydrogen, and can produce bubbles with dilute sulfuric acid, and aluminum produces bubbles quickly, and copper cannot react with dilute sulfuric acid, so D is correct;

So the option is: ad

(1) Figure A shows a wire made of metal, so it can be judged that the conductivity and ductility of metal are used.

So the answer is: conductivity or ductility;

2) Figure B shows the operation of scribing on the pure copper sheet with a brass sheet, therefore, it can be judged that the experiment is the hardness of the brass sheet and the pure copper sheet;

So the answer is: compare the hardness of brass with copper (or alloy with pure metal);

3) The activity of iron is stronger than that of copper, therefore, iron can react with copper sulfate solution to form ferrous sulfate and copper;

Therefore, the answer is: fe+cuso4=feso4+cu;

4) According to the highly active non-metal, the weakly active non-metal can be replaced from its solution, and the active Br2 ratio of Cl2 can be judged by the reaction Cl2+2Nabr=2NaCl+br2; From br2+2ki=2kbr+i2, it can be judged that br2 is more active than i2. Based on the above judgments, the relationship between the strength and weakness of the activity of the three non-metallic elemental cl2, i2 and br2 is as follows: cl2 br2 i2;

So the answer is: cl2 br2 i2;

According to the relationship between the strength and weakness of the activity of three non-metallic elements Cl2, I2 and Bri2: Cl2 br2 i2; It can be judged that Cl2, Ni2, NaCl, KCL, Nai, and Ki can be replaced by Cl2 and Nai and Ki, Cl2+2Ki=2KCl+I2 (or Cl2+2Nai=2NaCl+I2);

So the answer is: Cl2+2Ki=2KCl+I2 (or Cl2+2Nai=2NaCl+I2).

a. Bronze is a copper alloy;

b. Charcoal does not belong to alloy;

c. Pig iron belongs to alloy;

d. Solder is an alloy;

Therefore, choose B

a. Bronze is an alloy of copper and tin, so A is wrong;

b. Copper is composed of a substance called copper, which is a pure substance, and the alloy is a mixture, so copper does not belong to an alloy, so B is correct;

c. Pig iron is an alloy of iron containing carbon and other impurities, so C is wrong;

d. Solder is an alloy of tin and lead, so D is wrong;

Therefore, choose B