Usually made of iron and steel materials of brazing, picks, hammer, wrench, wrench, sling and other tools and equipment in the intense action or miss friction, strike sparks falls is hidden spark origin, so these tools cannot be used in explosive dangerous location.
Used in explosive dangerous location tools (equipment) must be made no friction and collision sparks, and even does not produce hot high temperature on the surface of the special material, such a tool called explosion-proof tools.
Steel material has high strength and hardness, suitable for making tools, and the strength and hardness of the steel increased with the increase of carbon content increased.
However to the steel material friction spark generating mechanism of the research results show that it is precisely in carbon steel is the root cause of friction spark.
In order to eliminate tool friction, strike sparks, people put the material direction of the steel.
Steel used for explosion-proof tools, compared with steel, there are two significant difference:
First, do not contain carbon. There will be no oxygen - iron - carbon chain reaction, so there's no spark.
Second, strength and hardness of the steel is relatively low, the thermal conductivity and higher than steel, friction or collision occurs, the local spot will occur plastic deformation and focus on individual contact, avoid friction energy and materials of high thermal conductivity, the heat generated by the friction quickly spread to the substrate and reduces the danger of friction hot heat point of impact.
The above two points is the explosion mechanism of the steel (copper) tools.
The strength and hardness of the pure copper is too low, however, cannot be directly used as a tool, you need to add the appropriate elements such as beryllium, such as aluminum, titanium, nickel, magnesium smelting copper alloy to improve its strength and hardness.
But as strength and hardness increase, the second characteristics of steel in the explosion-proof tools have weakened or in danger of disappearing. As a result, people and further explore the way of "the best of both worlds".
This is require the preparation of copper based alloys at room temperature with high strength and hardness, once by friction and collision, the temperature rise to a certain extent, the microstructure of copper base alloy phase change and the transformation for the low strength and plastic deformation and even wear off.
The local friction on the surface of the metal friction force, friction, the impact of the highest temperature is limited under the alloy phase transition temperature, be not ignite an explosive mixture of explosion proof alloy. Foreign called non dangerous spark of metal.
In the industry now has hinged bronze, aluminum bronze, J892 copper alloy and various copper alloy successfully applied in the explosion-proof tools.