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Question:

What should I pay attention to when designing a casting structure?

What should I pay attention to when designing a casting structure?

Answer:

1 of the casting in metal mold cooling was faster than sand, metal type and let, thus casting in metal mold casting, casting stress generated in the ratio of sand casting to crack tendency is also large, but also prone to misrun and cold lap, white (for casting casting). Defect. Usually: (1) in the prevention of metal casting casting crack aspect should pay attention to the following problems: the structure of A in wall thickness, wall transition and connection to the ease, corner fillet appropriate requirements such as should be more strict than sand casting; B should be connected vertically connected with the wall to tilt C; for the weak parts of the structure should be set to strengthen ribs, bosses, to prevent casting; D should minimize the obstacle free shrinkage of the boss, casting rib, flange and other prominent part; E in the casting arrangement of ribs, but also should consider its influence on the casting shrinkage.
The basic structure of unit 3 in the design of metal casting casting and its parameters are selected, usually should also pay attention to: (1) because of the metal type heat quickly, so the metal type casting minimum wall thickness should be bigger than the sand casting casting casting; (2) the inner wall of the internal ribs and the thickness of a should be connected the outer wall thickness of 0.6 to 0.7, or as the inner wall (rib) cold slowly, cracks in the wall at the junction in the casting shrinkage; (3) to prevent generating white grey cast iron, in addition to taking measures in the process, must make the wall thickness is not too thin (some information that cast fillet at the corner of the wall thickness of 15mm or more, with metal casting casting must be in the corner, for Aluminum Alloy, metal casting magnesium alloy castings shall not be less than 3 ~ 4m; (4) because of the metal type and the core that, for To facilitate the extraction of castings and casting out type, slope casting should be suitably large than sand casting metal casting, the general should be 30% ~ 50%, it should be pointed out that in addition to the height of the slope of casting size and alloy type, wall, is also related to the casting surface position, where the cooling and contraction of the metal type the surface of casting surface can be designed from the tendency of small inclination, while casting shrinkage tend to be pressed on the surface of metal casting type should be given greater inclination.
(2) in the prevention of metal mold casting misrun and cold partition should pay attention to the following problems: the structure of A casting thickness should be appropriate not too thin, especially when casting size when not too thin; the B should avoid a big level, because it makes the liquid metal in the casting. Rise slowly, and the air contact surface, easy oxidation, and because the metal type liquid metal heat quickly, quickly lose liquidity, easy to cause misrun and cold lap, slag and other defects; C casting shape should be streamlined to avoid sharp corners and has sharp change connection structure in order to facilitate the flow of liquid metal. 2 in the design of metal castings in a complex shape, if the production process is very difficult, should not affect the casting conditions, try to make the casting has simple shape, strong structure change, removed from metallic die for.

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