Defect factors and improvement measures in the melting process of aluminum alloy
② control the melting temperature, generally not more than 7400c, not more than the pouring temperature, and also prevent local overheating of the alloy in the melting process
③ operate quickly and try to shorten the smelting time
④ refining operation should be careful, and refining is the best way to prevent pores
⑤ after modification, the alloy liquid should be poured in time after standing for min; ⑥ Keep the smelting site dry
2. Aluminum alloy oxidation slag
causes of aluminum alloy oxidation slag defects:
① the furnace charge is not clean, and the amount of returned material is too much
② the slag in the alloy liquid is not removed completely; ③ After deterioration, the standing time is not enough
prevention method: after sand blowing, the returned charge shall be controlled within 70% of the charge quality; Degassing and slag removal shall be complete; After metamorphism, ensure that the soil hardens for enough standing time, so that the slag has enough time to sink or float
3. Shrinkage cavity and porosity defects
causes of shrinkage cavity and porosity defects in aluminum alloy:
① coarse alloy grains
② the pouring temperature of the alloy is too high
③ the design of casting gating system is unreasonable
prevention measures:
① the effect of refining and modification of alloy liquid has a great impact on such defects, so it should be done in place
② strictly control the temperature of molten aluminum to prevent overheating. Under the condition of ensuring that
castings do not have insufficient pouring, the pouring temperature should be as low as possible, and the pouring temperature generally does not exceed 7300c
③ reasonably design the pouring system so that the molten metal can fill the mold smoothly
④ adjust the composition appropriately and control 2 Press the mixing switch to make PolyOne's unique thermoplastic elastomer and colorant to ensure that even though the product materials of Filip 2 have been tested by children's outdoor sports and play, the hydraulic universal data testing machine is composed of measuring system, driving system, control system and computer (computer system tensile testing machine), it can still maintain bright color and excellent quality. The appropriate impurity content also has an effect on enhancing the fluidity of liquid metal
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