Characteristics of low pressure casting technology
(1) pouring pressure and velocity can be adjusted, it can be applied to various mold (such as metal type), casting castings of various kinds of alloy and all kinds of size.
(2) the bottom note type filling, liquid metal filling smoothly, no splash phenomenon, can avoid to get involved in the gas and the erosion type wall and core, raised the qualification rate of casting.
Crystallization under pressure, and
(3) casting casting compact structure, clear outline and smooth surface, high mechanical properties, the casting is especially advantageous for large thin wall parts.
(4) save the feeding riser, metal utilization ratio up to 90 ~ 98%.
(5) the intensity of labor is low, good working conditions, simple equipment, easy to realize mechanization and automation.
In terms of strengths and weaknesses (relative gravity gold casting)
Low pressure casting advantages and disadvantages
1) casting utilization rate is very high. (85 ~ 95%)
Since there is no riser and gating, gate is small, so can greatly reduce the cost of raw materials and processing time.
2) to obtain perfect castings. Less easy to form the directional solidification, the internal defects.
3) the involvement of the gas, sundry. Can change the compression speed, melting soup by laminar filling.
4) you can use the sand cores.
5) easy to realize automation, which can be more work, more process operation.
6) is not affected by the operator of proficiency.
7) the use of material is wide.
Table 5.1 material utilization casting method
Gravity mold casting of gold
High pressure casting
Low pressure casting
Material utilization (%)
45 to 55
50 ~ 60
85 ~ 95
1) gate scheme small degrees of freedom, thus limiting the product. (the product of gate location and quantity restrictions, internal wall thickness change, etc.)
2) casting cycle long, the productivity is poor. In order to maintain directional solidification and melting soup liquidity, die temperature is higher, solidification speed is slow.
3) need comprehensive strict management (temperature, pressure, etc.)