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Factors and methods required for roughness difference of die casting parts

The reasons for the difference in the smoothness of die casting parts and the improvement measures, reasonable arrangement of the inner runner, the place is raised to avoid the aluminum liquid directly washing the surface with the smoothness standard; Raise the chamfer, guide the aluminum liquid to change the orientation of the filling cavity, so as to avoid the pot liquid directly washing the relative position of the mold with the smoothness specification of the casting And effectively avoid the hot knot at the key position, reduce the bias of mold cracking. In the case that the product structure is not allowed, we can negotiate with the user to make moderate changes to the product structure or wall thickness to achieve the purpose, without affecting the assembly and product performance, and negotiate with the user to locally increase the transition Angle or process to avoid too small wall thickness and premature cracking of the mold. Before the product is developed, CAE analysis is carried out to obtain a more moderate pouring system, which can not only get a good quality, but also avoid high pouring rate and pressurization pressure to increase the mold life. The orientation and location of the original runner make the filling process of liquid aluminum longer. After changing the orientation and place of the inner runner, the liquid aluminum filling process is shorter, the two-stage rate and the boost pressure are lower to ensure the quality of the product, and the mold is not so easy to crack. Strengthen the mold maintenance, after using the standard several times, to carry out stress removal annealing treatment on the mold.

What is the aluminum alloy casting production process

After aluminum alloy casting production, the voltage enters a more orderly and slow rising stage. It shows that the non-porous layer is continuously decomposed and the new non-porous layer is growing at the same time, that is to say, the transformation efficiency of the non-porous layer in the oxide film is balanced with the decomposition rate, so the thickness of the non-porous layer is not easy to rise again, and the voltage change is small. However, at this time, the transformation and decomposition of the oxide film at the bottom of the hole can not be stopped, and they are still continuing to develop, resulting in the bottom of the hole gradually moving into the metal matrix. With the increase of oxidation time in aluminum alloy casting production, porosity occurs as holes increase, and the film layer with porosity gradually thickens. When the film conversion rate and decomposition rate achieve dynamic balance, even when the oxidation is promoted, the thickness of the oxide film will not rise again, and the anodizing stage should be stopped. Within the first few seconds to tens of seconds of switching on electricity, the surface of aluminum is directly transformed into a layer of tight, with high insulation properties of oxide film, thickness of about 0.01 ~ 0.1μm, for a layer of continuous, non-porous film layer, called the non-porous layer or barrier layer, the film occurs when the current passes through and the film layer thickens again. The oxidation process in aluminum alloy casting production is easy, the liquid is orderly, the operation process is convenient, the debris composition is allowed to be wide, the power consumption is less, the cost is reduced, and it can almost be more suitable for the processing of aluminum and various aluminum alloys, so it has been widely used in China

Solutions to prevent shrinkage in the production of cast aluminum parts

To avoid the casting has shrinkage holes and shrinkage porosity, for the shrinkage and condensation characteristics of the alloy to develop a reasonable casting technology, so that the casting in the condensation link to create excellent feeding standards, as far as possible to avoid the shrinkage into shrinkage holes, and shrinkage holes occur at the end of the casting condensation area. In this way, a gate of a certain size is placed in the area of condensation at the end of the casting, so that the shrinkage hole is concentrated in one place, or the gate is opened in the area of condensation at the end of the immediate shrinkage. In order to create an excellent feeding standard for castings in the setting stage, the key factor is to control the setting direction of the casting to make it conform to the "directional setting criteria" or "co-setting criteria". The entry point of the pouring system has a key hazard to the temperature spread of the casting. Adjusting the pouring temperature and pouring rate of the liquid metal can strengthen the directed condensation or the condensation together. Setting gate on thick wall or hot joint of casting, casting aluminum is an effective process countermeasure to avoid shrinkage and shrinkage. The flexible use of gate, subsidy and cold iron is a reasonable countermeasure to remove shrinkage and porosity in castings The pressure processing deformation and die casting are effectively and closely combined together to make the aluminum workpiece get effective strength and patience cooperation method called deformation die casting; The die casting carried out in the negative pressure atmosphere or vacuum is called vacuum die casting, which can not only make the workpiece non-corrosive, non-carburizing, the surface of the workpiece after continuous treatment, and the function of the workpiece, but also carry out chemical die casting through the infiltration agent. In order to only warm the surface of the workpiece without excessive heat transfer into the workpiece, the applied heat source must have a high energy density, that is, provide a lot of heat energy on the workpiece per unit area, so that the surface of the workpiece or some can reach a high temperature for a short time or instantaneously.

Knowledge of quality requirements of cast aluminum parts

The cast aluminum parts can be made at will in a variety of complicated styles, and can also make better accuracy requirements, and the surface gloss is also qualified. These characteristics reduce the machining amount of cast aluminum parts and the casting surplus of metal at large layers. It not only saves power energy, metal materials, but also saves labor costs at a large level. It is also because of the advantages of all levels of cast aluminum parts, which are widely used in many fields such as automobile manufacturing, internal combustion engine production, motorcycle production, and electric motor production. The common use of cast aluminum parts is used for accessories on modern cars. The quality of cast aluminum parts includes appearance quality, internal quality and use quality. Appearance quality refers to the roughness, surface quality, standard tolerance, form and position tolerance and quality error of the casting surface. The internal quality refers to the chemical composition, physical and mechanical properties, metallographic structure and the holes, inclusions and cracks in the casting. Service quality refers to the casting can meet various requirements and working performance The excellent casting temperature of cast aluminum parts will keep the liquid metal stable, thereby reducing the organizational stress and avoiding cracks. Generally, the casting temperature should be determined according to the type of material and the size of the ingot. If the temperature is not appropriate, it will increase the internal stress and promote cracks or cracks in the casting. The temperature is too low, it is not good, because this will make the surface of the ingot appear cold insulation, slag inclusion and other defects, and even cracks, serious, it will make the casting can not be achieved again. 逐句对照

Cast iron in 8 steps

2. Pad the support point well and pad flat to ensure that each support point is evenly stressed and the entire plate is stable. 3, the installation of each support point of the cast iron plate with adjustment pad iron pad, pad, by professional and technical personnel to adjust the plate to qualified accuracy. 4, the use of light to gently release the workpiece, do not move more rough workpiece above, so as not to cause damage to the working face bump, scratch and so on. 5, in order to prevent the overall deformation, after use, the workpiece should be taken off the cast iron plate to avoid deformation caused by long-term pressure on the workpiece. 6, when not in use, the working surface should be cleaned in time, and then coated with a layer of anti-rust oil, and covered with anti-rust paper, and the cast iron plate is covered with outer packaging to prevent damage to the working surface caused by carelessness. 7, should be installed in a ventilated, dry environment, and away from heat sources, corrosive gases, corrosive liquids. 8, the implementation of regular weekly inspection according to the standard, the verification cycle can be 6-12 months according to the specific situation.