When is the best use of copper sleeves?
When is the best time to use the copper sleeve? What are the methods of casting copper sleeves? What are the defects in copper sleeve casting? How to solve the
defect of copper sleeve casting? Copper sleeve is a very broad name. The copper sleeve is a component used in sliding rotating machinery to reduce friction and at the
same time transmit thrust and support the fixed role of the copper sleeve manufacturer. Commonly used materials for copper sleeves include ZCuSn10Pb1, ZCuSn10Pb5,
ZCuPb10Sn10, ZCuPb15Sn8, ZCuZn38Mn2Pb2, etc. Copper sleeves are also called "bronze bearings". The process of copper sleeve production includes: forging, heat
treatment, and grinding process monitoring, and finally, logo management is required. So what are the methods of casting copper sleeves? Let's find out now.
When is the best use of copper sleeves? Method of casting copper sleeve:
1. The most common copper gasket method used in sand casting production is sand casting, which has the advantages of wide adaptability and relatively simple production
preparation. However, the dimensional accuracy, surface quality, and internal quality of the castings produced by this method are far from meeting the requirements of
mechanical parts, and the production process is more complicated. The realization of mechanized and automated production requires huge investment. In the production of
some special parts and special technical requirements When castings, the technical and economic indicators are low, so the application of sand casting in casting
production is subject to certain restrictions.
2. In addition to sand casting, special casting has formed many other casting methods that are different from sand casting by changing the casting material, pouring
method, liquid alloy filling mold form or casting solidification conditions and other factors. Foundry workers collectively refer to other casting methods that are
different from sand casting processes as special casting. Common special casting methods in the machinery manufacturing industry are:
(1) Investment casting. It is a method of casting non-cutting or less-cutting castings with higher dimensional accuracy and lower surface roughness by using fusible
models and high-performance mold shells (molds).
(2) Metal mold casting. It is a method of using metal molds to increase the cooling rate of castings, realize multiple castings in one type, and obtain castings with
dense crystalline structure.
(3) Pressure casting. It is a method of obtaining precision castings by changing the filling and crystallization and solidification conditions of the liquid alloy,
so that the liquid alloy is filled into the mold under high pressure and high speed conditions, and is formed and crystallized under high pressure.
(4) Lost foam casting. It is a combination of foamed plastic models similar in size and shape to the castings into a model family. After brushing with refractory
coating and drying, it is buried in quartz sand for vibration modeling, and then liquid metal is poured under certain conditions to vaporize the model. And make the
molten metal occupy the position of the model, and the required casting is formed after the molten metal solidifies and cools.
(5) Centrifugal casting. It is a method that uses centrifugal force to cast special castings such as sleeves by changing the filling mold and solidification
conditions of the liquid alloy.
(6) Ceramic mold casting. It is a casting method for obtaining thick and large precision castings by changing the casting material, selecting high-quality refractory
materials and binders, and using a special grouting method to obtain a cavity with precise dimensions and a smooth surface.
(7) Low pressure casting. It is a casting method between gravity casting (referring to the process of injecting molten metal into the mold under the action of the
earth's gravity) and pressure casting. By changing the filling and solidification conditions, the liquid alloy is smoothly filled into the mold from bottom to top
under low pressure and low speed conditions, and under the action of low pressure, it crystallizes and solidifies from top to bottom in order to obtain high-quality
castings with dense structure.
(8) Vacuum suction casting. It is a method of obtaining castings by creating negative pressure in the crystallizer (mold) to attract liquid alloys, and crystallizing
and solidifying the liquid alloys in a vacuum. This method changes the filling and solidification conditions of the liquid alloy, reduces the gas absorption and
oxidation of the liquid alloy, and is suitable for casting high-quality castings such as rods, barrels, and sleeves.
(9) Continuous casting. It is an efficient production method for casting pipes and ingots under the conditions of continuous pouring, solidification and cooling
through a fast-cooling crystallizer.
(10) Extrusion and liquid stamping casting. It is a comprehensive processing method of casting and forging processing.
The choice of centrifugal casting speed:
① The mold speed should ensure that the copper liquid enters the mold and can form a cylinder under the action of centrifugal force.
②Fully use centrifugal force to ensure good internal quality of castings.
③When using the vertical centrifugal casting method to cast the centrifugal casting copper sleeve, it can make full use of the centrifugal force to play the copper
liquid filling ability and the ability to feed the casting.
When is the best use of copper sleeves? Precautions in the casting process of copper price copper sleeve: the nature of the copper sleeve is high in hardness,
excellent wear resistance, not easy to seize, has good casting performance and machinability, and has good resistance in the atmosphere and fresh water. Erosive. Due
to the loose and porous metal structure in the production of copper sleeves, the process requirements must be strict during the electroplating process.
1. The actual surface area of the copper sleeve is many times larger than the calculated surface area. The impulse current density during electroplating is about 3
times higher than that of ordinary parts, and the pre-plating time is also longer than that of ordinary parts.
2. When plating silver, the tank must be charged with electricity, and the impulse current density shall be used for electroplating for 5 minutes under the premise of
shaking the workpiece, and then it shall be converted to normal current density.
3. When pre-plating copper, the parts and the hanger should be shaken frequently to ensure the uniformity of the coating color and prevent the phenomenon of mottling
during silver plating that affects the appearance of the coating.
4. The cleaning of each process should be thorough to prevent the solution remaining in the pores from affecting the next process.
Is there a difference between cast copper sleeve and forged copper sleeve? Casting is to melt the metal and then flow it into a cavity with a specific shape. After
solidification, a specific shape is formed. Forging is to heat the metal, but it is still solid, and then place it on a platform or a mold of a specific shape, using
an air hammer. Such tools are forged into specific shapes.
After talking about copper sleeve casting, let’s go back and talk about the working principle of copper sleeve: the effect of copper in the hollow shaft is also used
as a sliding bearing. The friction of the sliding rotating work shaft on the bearing, the lubrication system usually requires additional work . The sliding bearing
works smoothly, reliably and without noise. Under fluid lubrication conditions, it is separated from the sliding surface without direct contact with the oil, but it
may also greatly reduce the friction and wear of the surface. The film also has vibration absorption capacity.
When is the best use of copper sleeves? When is the best use of copper sleeves? The copper sleeve should be used after heat treatment, because the strength of copper,
especially the plasticity and toughness decrease. In order to refine crystal grains, uniform structure and eliminate internal stress, the copper sleeve must be
normalized or annealed. After normalizing the copper, the high cost of the machine performance after annealing also becomes lower, so it is widely used. However, the
normalizing treatment results in a larger internal force than annealing, which is only suitable for copper parts with a carbon content of 0.35%. Low-carbon copper
parts have good plasticity and are easily broken when cooled. After the internal force becomes smaller, the copper sheet should be tempered at high temperature after
normalizing. For carbon content. 0.35%, complex structure and easily cracked copper parts can only be annealed. Copper parts should not be quenched, otherwise they
will easily crack.