Machining MaterialMachining Methods

Control Of Key Processes In Aluminum Extrusion Workshop

1. According to the operation plan, select the mold that conforms to the plan, flat mold: 460℃—480℃ . Split mold: 480℃–500℃. The residence time of the mold in the furnace is not longer than 8 hours, and the process of loading the mold should be quick and fast, and the mold should be prevented from cooling.

2. The ingot barrel must be kept clean, without serious wear or belly, otherwise, slag or bubbles will appear in the extruded product.

3. The aluminum alloy round ingots are not allowed to roll on the ground. Any silt or dust on the surface should be cleaned and then heated in the furnace.

The temperature setting of the aluminum rod heating furnace is set at 300 ℃-450 ℃ in the heating stage. The temperature control when the aluminum rod is put on the machine. According to the wall thickness, it should meet T ≥ 1.4mm to control the temperature at 440 ℃-540 ℃, T <1.4mm temperature Control at 400 ℃-540 ℃, depending on the variety, mold structure, alloy type.

4. Before the aluminum alloy round ingot is heated in the furnace, the surface quality self-inspection should be carried out. The self-inspection is the responsibility of the host. Any round ingot with obvious slag inclusions, cold insulation, center cracks and bending should not be entered into the furnace. Heating, it should be selected and returned to the casting workshop.

5. In the form of a ladder temperature of 100 ℃/1 hour heating, the ingot cylinder is heated to 380 ℃-420 ℃. The temperature of the end surface of the ingot cylinder is 280℃—360℃

6. The end face of the ingot barrel and the mold should be flat without damage and aluminum sticking, otherwise it will run out of material during extrusion. During the extrusion process, the squad leader must measure the temperature with a portable thermometer every 10-20 ingots and make a good record to keep track of the temperature changes of the ingot at any time and maintain the normal extrusion temperature.

7. When squeezing, pay attention to changes in pressure. The starting pressure should not exceed 210kg/cm2. During normal extrusion, the pressure will drop with the process. If the pressure does not drop more than 1 minute after the starting pressure, the extrusion should be stopped to prevent damage to the equipment and mold.

8. The extrusion speed should be controlled according to the different characteristics of different alloys. The extrusion speed of low impurity alloys can be higher, and the extrusion speed of high impurity alloys will be slower. If the temperature of the aluminum rod is too high, the extrusion speed should be reduced. If you want to increase the extrusion speed, the temperature of the aluminum rod should be controlled lower.

9. In order to control the lower temperature of the discharge port of the mechanical properties, it must be ≥500℃.

10. Inspection of the first piece: the first profile extruded from the upper die should cut its material head 500mm long and leave it as the basis for repairing the mold, and the first and second rods should be cut off 500mm long to be inspected by the inspector for appearance dimensions Check the tolerance of shape and position to confirm whether it meets the requirements of drawing size and assembly relationship, so as to determine whether the mold can continue production.

11. In order to prevent aluminum sticking to the end surface of the mold, the end surface of the ingot barrel and the end surface of the extruded gasket, a small amount of release grease is allowed to be applied to the end surface of the mold and the end surface of the gasket, but it should be coated or not as much as possible, and it is not allowed to coat the mold The cavity of the cavity and the inner wall of the ingot barrel to prevent the grease from polluting the profile.

12. To use the squeeze gasket correctly, protect the squeeze gasket from being bruised. When the extruded gasket wears too much and becomes rounded and the cylinder is not clean, the new gasket should be replaced in time. Every time you squeeze, you must pay special attention to whether the gasket has been placed to prevent equipment accidents caused by the failure to squeeze the gasket.

13. In the process of aluminum extrusion, attention should be paid to the change of hydraulic oil temperature: when the oil temperature rises to about 45-50 ℃, the extrusion force will be greatly reduced, the extrusion opportunity becomes weak, at this time should stop and try to After the oil temperature drops, it can be squeezed again.

14. The tonnage (tons) of aluminum profile extrusion machine is 60010001650, and the number of ingots (extreme) 100-15060-8040-80 is extruded by each set of molds at one time.

15. In order to prevent the gas and dirt in the dead zone of the extrusion from flowing into the aluminum profile and in order to protect the extrusion rod from being damaged, the limit length of the excess pressure is not allowed to be too thick, nor is it allowed to be thin, the excess pressure is controlled to 15-30mm thickness.

16.6063 Extruded aluminum profile is quenched by forced air cooling in T6, T5 is naturally cooled, and the profile should not be cooled to below 170°C at a rate not less than 80°C/min. The 6061 extruded profile is quenched by strong wind, water mist or direct water cooling, and the temperature should be reduced to below 200°C in 2-3 minutes.

17. Aluminum profiles must be cooled to below 50°C before being straightened on a cold bed. When the profile is straightened, the amount of straightening should be controlled at about 1-2%. The straightening deformation of the ultra-thick profile is allowed to be slightly larger, but not more than 3%. When straightening, pay attention to protect the decorative surface from being scratched, and try to make the non-decorative surface contact the scaffold conveyor belt as much as possible.

18. Before the aluminum profile is fixed, its length tolerance requirements should be clear. If the customer has special requirements, it should be implemented according to the customer’s requirements; if there is no special requirement, the length tolerance will be controlled by +15mm, and when delivered in multiples, the total deviation is +20mm. After calibrating the fixed length, check whether the length of the first profile meets the requirements. It must be a positive deviation, and no negative deviation is allowed. After confirming that there is no error, start sawing in batches of fixed length.

19. In order to prevent the aluminum profiles from being scratched, do not stack the profiles and cut them. When the profiles are moving forward, the aluminum scraps on the sawing table should be cleaned first.

20. When sawing, the saw blade should be lubricated with oil, but the lubricating oil should be prevented from sticking to the surface of the aluminum profile. 20 After sawing, the cutting edge of the aluminum profile should be perpendicular to the axis, and the cutting edge should be free of burrs, flashes and distortions. In order to have a beautiful cutting edge, you should always keep the blade sharp, and pay attention to removing the aluminum accumulation on the blade. When the blade is not sharp enough, it should be replaced in time to polish the saw teeth or use a new blade.

21. After sizing the aluminum profile, use compressed air to blow away the aluminum shavings, and then install the frame.

22. After the aluminum profile is sized, the large materials are checked one by one, and the small and medium materials are checked at a rate of 10%. The inspection content is flatness, curvature, twisting, opening, closing, and surface quality.

23. After the aluminum profile is sized and checked, two people should gently lift it and place it in the material frame, carefully arrange it neatly, do not collide and rub against each other. Clean gauze gloves should be worn when framing. Gloves must be free of oil, water and other dirt. When installing the frame, the long and heavy materials are on the lower layer of the frame, and the short and light materials are on the upper layer of the frame.

24. After laying one layer, according to the length of the aluminum profile and the degree of its own weight, 4-8 horizontal spacers should be placed properly, and then the second layer of aluminum profile should be placed. The profiles are not allowed to bend and stack up.

25. For all solid aluminum profiles that cannot be ventilated in the longitudinal direction of fine materials, small square tubes with ventilation holes should be separated by layers to facilitate heat transfer with aging.

26. The plane of the upper layer of aluminum profile is lower than the plane of the material frame to prevent the profile from being crushed when the frame is stacked.

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