Low pressure casting and Gravity casting.docVIP

低压铸造和重力铸造 Low pressure casting and high pressure casting? 低压铸造是液体金属在压力作用下充填型腔，以形成铸件的一种方法。由于所用的压力较低，所以叫做低压铸造。其工艺过程是：在密封的坩埚（或密封罐）中，通入干燥的压缩空气，金属液在气体压力的作用下，沿升液管上升，通过浇口平稳地进入型腔，并保持坩埚内液面上的气体压力，一直到铸件完全凝固为止。然后解除液面上的气体压力，使开液管中未凝固的金属液流坩埚，再由气缸开型并推出铸件。 Low?pressure?casting?is?a?method?of?molten?metal?fills?the?cavity?under?the?pressure?and?then?forms?the?casting?.due?to?the?pressure?is?not?high?,so?it?is?called?low?pressure?casting?.The?technical?process?is?:?in?the?hermetic?crucible?(or?sealed?pot?)?injecting?the?dry?compressed?air?,molten?metal?under?the?effect?of?gas?pressure?goes?up?along?the?pipe?then?through?the?gate?placidly?run?into?the?cavity?,then?keep?the?gas?pressure?upper?the?liquid?in?the?crucible?until?the?casting?solidification?totally?.then?remove?the?gas?pressure?to?make?the?unfreezing???metal?in?the?pipe?for?opening?run?back?into?the?crucible?and?at?the?same?time?use?the?cylinder?open?cavity?to?detrusion?the?casting?.? 低压铸造独特的优点表现在以下几个方面：?? The?unique?characteristics?of?low?pressure?casting?performed?as?below?:? 1．液体金属充型比较平稳；??Molten?metal?full?the?cavity?smoothly.? 2．铸件成形性好，有利于形成轮廓清晰、表面光洁的铸件，对于大型薄壁铸件的成形更为有利；?? The?forming?property?is?good?and?in?favor?of?forming?the?edge?shapeness?and?surface?bright?and?clean?.It?is?favorable?for?the?large?casting?parts?with?thin?section?casting? ?3．铸件组织致密，机械性能高；?? The?tissue?of?casting?is?densification?,and?mechanical?behavior?is?high?.? 4．提高了金属液的工艺收得率，一般情况下不需要冒口，使金属液的收得率大大提高，收得率一般可达90％。?? 低压铸造独特的优点表现在以下几个方面：?? The?unique?characteristics?of?low?pressure?casting?performed?as?below?: ?1．液体金属充型比较平稳；??Molten?metal?full?the?cavity?smoothly.? 2．铸件成形性好，有利于形成轮廓清晰、表面光洁的铸件，对于大型薄壁铸件的成形更为有利；?? The?forming?property?is?good?and?in?favor?of?forming?the?edge?shapeness?and?surface?bright?and?clean?.It?is?favorable?for?the?large?casting?parts?with?thin?section?casting? ?3．铸件组织致密，机械性能高；?? The?tissue?of?casting?is?densification?,and?mechanical?behavior?is?high?.? 4．提高了金属液的工艺收得率，一般情况下不需要冒