Le cuivre joue un rôle important dans la vie des êtres humains. De la fourniture d'électricité à l'approvisionnement en eau, le cuivre a rendu tout possible.
It allows the electric current to passes through it with the same voltages; it is the good conductor of electricity.
The copper is used in the electric appliances, almost every high-quality motors have the copper wires in them.
In the past, the cutlery item is made from the copper with are a good conductor of the heat and cold. Copper itself is soft in nature but when you mix it with any other metal it becomes hard.
Quelle est la dureté des métaux?
Hardness is termed as the resistance of the metals to indentation. Hardness doesn’t remain forever it depends on the strength and the plasticity of the metal.
The hardness of the metal depends on the method of measurement. The measurement results are expressed in the quantitative figures.
The resistance in the metal can make them hard, resistance refer to the four different things. They are scratching, abrasion, cutting, and penetration.
The different properties of the metal give them the ability to resist or deformed permanently when the load is applied. The greater resistance to deformation shows the greater hardness of the materials.
The hardness of the material is commonly used for the quality testing and quality control of the materials.
The main reason for the quality control of the materials is because they are fast and known to be the nondestructive tests. There are some of the important measurements for the hardness of the materials described below:
Dureté d'indentation: c'est la méthode simple dans laquelle nous pouvons mesurer la résistance du matériau à la déformation lorsque la pression ou la charge constante de l'objet tranchant lui est appliquée. Il peut être mesuré à travers le Rockwell, Brinell, les rives et les Vickers.
Dureté aux rayures: dans cette méthode, nous mesurons la résistance du métal à la déformation plastique permanente ou à la rupture due au frottement de l'objet pointu sur celui-ci. Pour la mesure de cette méthode, l'échelle de Mohs est utilisée.
Harnais de rebond: rebound hardness is the method in which the diamond-tipped hammer is dropped from a certain height on the specific material to check its hardness. The Bennett hardness and the Leeb rebound hardness scale are used to measuring the rebound hardness.
The conversion table is used to convert the one scale to another; it is used for the practices. There is an individual measurement scale for each of these classes.
Propriétés du cuivre: (liées à la dureté)
The copper is used for the sheeting and in the form of strips commonly. It is consists of 99.9 percent pure copper and the 0.1 percent may be the other metal.
The pure form of the copper is soft which is extremely malleable and can be used for the different applications like intricate ornamental works.
In the past, it is commonly used in the construction of buildings. The heavy gauge materials are used along with the copper because copper has a low strength than other metals.
With the passage of time, the copper is replaced with other strong metals in the building constructions.
Many years ago the cold-rolled copper is introduced and the gauge of the other materials is reduced.
The cold-rolled copper has a long life with low maintenance than other materials.
Cold rolled copper is hard and is less malleable than the soft tamper copper. It is the popular form of copper which is used in construction purposes.
The common mechanical properties of the copper are strength, hardness, and ductility which determine its condition.
Copper is can be converted into the hard from soft; the method used to range the copper is cold working. Annealed (soft) copper is 40HV of hardness with the tensile strength of 200 N/mm2 and after the cold work, it has the hardness of 110 HV with the tensile strength of 360 N/mm2. The ductility of the annealed copper is greater than the cold-worked copper.
You can increase the strength and the hardness of the copper easily. The common way of increasing the strength of the copper is through the alloying, but it can affect the conductivity of the electricity.
The hardening process is done by heat treatment and can result in the tensile strength of 1500 N/mm2.
Test de dureté:
Il existe différents types de tests pour déterminer la dureté des métaux, mais dans le cas du cuivre, seuls trois types de tests différents sont utilisés pour déterminer sa dureté. Les types de tests sont discutés ci-dessous:
Test de Rockwell:
The Rockwell Hardness test is a popular test to check the hardness of the copper. It consists of thirty different tests with the number of loads and indenter configurations.
Scale B and C are only used for the thickness of the 1mm and can be used for the copper alloys with this thickness. For the thin products the testing should be done through the superficial scales N and T. the hardness of the thin materials are checked with the microhardness scales.
Test de Brinell:
It is a large and extensive indentation test, which is not suitable for the thin and wire type materials. It is popular for testing the large rods, bars, plates, and other heavy materials.
The testing of these materials will produce large indentations. The Brinell test is run only for the materials who are thicker than the minimum of 3.2 inches.
Tests Vickers et Knoop:
The Vickers test is also known as the diamond pyramid hardness test. The load uses in this test is between 1 to 120 kg. If the weight of the material is less than 1 kg than the Vickers microhardness test will perform. And the knop test is specially designed for the micro indentation hardness testing.
The testing is performing with the help of the elongated indenter.
Tous les tests ci-dessus sont conçus pour vérifier la dureté du cuivre, la sélection des tests dépend de la qualité et du type de cuivre.