How to solve the blackening of aluminum alloy cutting fluid processing!
April 02, 2022
Aluminum alloy processing is naturally inseparable from the use of processing aids such as special cutting fluids for machining centers and aluminum alloy cutting oils. Improper selection of the special cutting fluid for the machining center will easily cause sticking to the knife, scratches, burns, oxidation of the workpiece, blackening, yellowing, whitening, and even deterioration and odor of the cutting fluid during processing. So once this problem occurs, how should we solve it?
The problem that is easy to occur in the process of aluminum alloy processing is the oxidation problem. Different aluminum alloys have different characteristics and their requirements are also different. In the selection of cutting fluid materials, a neutral cutting fluid with low alkali content and a pH value of about 7.0~8.5 is selected, because alkali is very corrosive to aluminum, magnesium, zinc, iron, etc., and alkali can aggravate the movement between metal ions. The experiment shows that when the aluminum is immersed in the alkaline liquid of PH10, a large number of bubbles are quickly generated on the surface of the aluminum parts, and the surface of the experimental aluminum is blackened in just 10 minutes. The original smooth and flat aluminum surface has become pitted and severely corroded. Can the ph value of the cutting fluid be too low to solve the aluminum corrosion phenomenon? When the raw materials are properly selected, the cutting fluid has a certain prolongation effect on the corrosion of aluminum alloys, but it does not play a fundamental role in the protection of aluminum. Too low ph of the cutting fluid is very unfavorable for the rust protection of production equipment, machine tools, etc. In addition, when the pH of the cutting fluid is low, it is easy to create a good breeding space for various bacteria, resulting in the deterioration and odor of the cutting fluid, which greatly reduces the service life of the cutting fluid.
How to resolve this contradiction? Practice has proved that adding 0.5% atwell-2815 in the concentrate can be very effective to deal with this situation. Atwell-2815 has a corrosion inhibition efficiency of 98% for aluminum and aluminum alloys in high and low pH environments, and can effectively protect aluminum alloys from blackening and discoloration even in strong alkali (ph9.5) environments. polyether is a linear polymer obtained by copolymerization or ring-opening homopolymerization with ethylene oxide EO, propylene oxide PO, butylene oxide BO, etc. as raw materials under the action of a catalyst. The new synthetic oil has good cleaning properties, lubricity, stability and water solubility, and has been widely used in various processing aids. But any kind of material is not omnipotent, it has advantages and there must be disadvantages objectively. Polyethers are often used for emulsifying, dispersing, and water-based synthetic lubrication in cutting fluids. At the same time, it was found that polyether has a very strong defoaming effect, because the molecules of polyether can penetrate the surface of the foam to destroy the stability of the foam, resulting in the rapid exception of the foam under the action of air pressure. In stubborn foam cutting fluids that are difficult to defoamer, polyether has a very strong and excellent defoaming and foam suppressing effect. Due to the strong permeability of polyether, when the cutting fluid is processing some auto parts, NdFeB, optical glass and other parts with rubber components, it will have a serious negative effect on rubber peptization and swelling. . Especially in the process of processing metals that require high inter-process rust prevention, the addition of polyether should be more careful, because polyether has a very strong polarity, which greatly offsets the rust resistance of cutting fluids.
