10 big drawback analyse aluminous Die Casting (graph article is united in wedlock, photographic)

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  • source:CLAREY CNC Machining
Die Casting (Die Casting) it is foundry technology of a kind of metal, its characteristic is to use mould antrum to bring to bear on to melting metal high pressure, be similar to plastic Injection Molding. Die Casting suits to make particularly many medium or small cast, because this Die Casting is,one the most extensive kind is used in all sorts of foundry technology. With other cast technical photograph to compare, the surface of Die Casting more level off, have taller size consistency. However, non-standard operation and parameter also can produce phyletic and numerous limitation. One, flow mark and decorative pattern visual examination: Cast has the streak that agrees with direction of metallic fluid flow apparently, have the grain of tropism of apparently visible as different as metallic matrix color not in the proper way, without development trend. When does the account that flow mark produces have as follows: (1) the model is lukewarm too low; (2) runner design is bad, inside runner position is bad; (3) makings is lukewarm too low; (4) fill rate is low, fill time is short; (5) gating system is unreasonable; (6) exhaust is undesirable; (7) sparge is unreasonable. 2, meshy Mao Chi (chap grain) 　 visual examination: Die Casting like having meshy hair silk apparently raised or sunken trace, increase along with Die Casting frequency and expand ceaselessly and outspread. Generation reason is as follows: (1) surface of antrum of Die Casting model has flaw; (2) warm-up of Die Casting model is inhomogenous. 3, cold lie between visual examination: Die Casting the surface has apparent, irregular, cave in linear grain (have penetrable with not penetrable two kinds) figure is fine and long and narrow, hand over the brim sometimes smooth, there is disconnecting possibility below outside force action. Generation reason is as follows: (1) two metals shed mutual butt joint, but not complete fusion and without meantime of existence of be mingled with, two money paid for shares belong to adhesion very fragile; (2) pouring temperature or on the low side of temperature of Die Casting model; (3) runner position incorrect or flow transient long; (4) fill rate is low. 4, depression (dent) 　 visual examination: In Die Casting of thick much have flowing dent apparently (shape is like dish of dish) . Generation reason is as follows: (1) cause 　 Die Casting by systole design undeserved wall large difference is too big; Runner position is undeserved; Pressure shoot than depress, dwell time is short; Die Casting model is local temperature is exorbitant. (2) cooling system design is unreasonable; (3) fly a model premature; (4) pouring temperature is exorbitant. 5, moulage visual examination: The mark that cast surface and place of contact of surface of antrum of Die Casting model leave or cast apparently trace of occurrence a flight of stairs. Generation reason is as follows: (1) give component to cause ejector pin end panel to be worn away by the top; Ejector pin adjusts accident abhorrent; Part of joining together of antrum of Die Casting model and other part cooperate bad. (2) cause by joining together or mobile part set spell a part to become loose; Mobile part becomes loose or wear away; The sidewall surface of cast, by move, the mold insert place of fixed die and mutual thrust deep into the enemy forces is formed. 6, bur trace visual examination: Flake shape and metal or metalloid receive with matrix part frit of the metal, flake below the action of outside force flake account other people, the cast surface some after flaking shines, some is dark gray. Generation reason is as follows: (1) there are metal or metalloid hangover in surface of antrum of Die Casting model; (2) pouring when take foreign matter to be added in first model antrum apparently. 7, statified (clip skin and flake) 　 visual examination or destroy an examination: In cast local the apparent arrangement that has a metal. Generation reason is as follows: (1) mould tigidity is not quite in process of metallic fluid fill, pattern plate generation shakes; (2) in control appearance of occurrence crawl of the drift in shooting a process; (3) runner system design is undeserved. 8, attrition ablation visual examination: Die Casting the surface is in certain produce coarse range locally. Generation reason is as follows: (1) by Die Casting model (model) cause inside the positional direction of runner and appearance are undeserved; (2) by what cast a condition to cause inside fluid of runner place metal erodes the refrigeration of acuteness place is insufficient. 9, erosive visual examination: Die Casting local seat has hemp dot or wale. Generation reason is as follows: (1) inside runner place setting is undeserved; (2) cooling condition is bad. 10, crackle visual examination: Put cast in alkalescent solution, crackle place shows dark gray. The destruction of metallic matrix and fission are shown linear or wave line form, grain is narrow and long, there is development tendency below outside force action. Generation reason is as follows: (1) content of the iron in alloy exorbitant or silicon content is too low; The content of harmful impurity in alloy is exorbitant, reduced the plasticity of alloy; Copper alloy of aluminum-silicon alloy, aluminous silicon contains zinc or contain copper the quantity is exorbitant; Magnesian amount is contained in aluminum-magnesium alloy overmuch; (2) time keeping a standard is too short, dwell time is short; Cast wall is large the place that has acuteness change; (3) local bag close power is too great, power gets when the top goes out not all. CNC Milling