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Ceramic foam filters in the stress analysis of molten metal


Ceramic foam filters in the liquid metal. Whether the filter is placed in any position gating system. Will be subject to the flow of molten metal impact, but also to withstand the static pressure of the molten metal:

(1). In the pouring cup is mainly the impact of molten metal;
(2). In the lower end of the sprue by the maximum impact and static pressure of the molten metal;
(3). By low impact and greater static pressure at the runner;
(4). Including runner at that minimal impact and greater static pressure.


Ceramic foam filter broken Phenomena

Filters used in current production refractory aggregate are much higher than the melting point of the liquid metal temperature, but due to the selection and design of the filter was not likely to break, for two main reasons:

(1) because the filter is not enough refractoriness, high temperature liquid metal softening effect, a sharp decrease in strength, if the impact force exceeds the upper limit of its exposure, the filter will partially broken;
(2) Filter poor thermal shock resistance, leading to cracking of the filter caused by thermal shock when broken. If debris into the casting, can make casting scrap, so how reasonable and safe and effective use of filters is very important.


Measures to avoid foam ceramic filter water wear

(1). Depending on the casting process, a targeted selection of filter types and specifications, as far as possible by less than the upper limit of the filter to withstand the design size, try to spread placed in the runner, so that the molten iron through each filter is not exceeded.
(2). Avoid concentrated liquid iron through the filter a site, make full use of the entire filter overcurrent; only when the filter is placed in the cup or sprue gate lower, you can tilt the filter placed in the ceramic base, reduced iron hydraulic impact.
(3). Try to use a large aperture filter, in order to avoid shortening the pouring time.
(4). Large cast member in particular wind power in overrun use, but also take the following security measures: ceramic foam filter placed below straight holes ceramic support; as far as possible not more than three consecutive placement; recommend appropriate warm-up filter conditions is to about 100 degrees.
(5). Initial use filters or production process changes must be done to verify, confirm castings meet the quality requirements, the filter is not damaged and then be put into mass production.