banner
TH EN
banner7
About us united productTechnical issue News Metal knowledge Contact us
Home
product category
Master Alloys
Cadmium free solders
Sterling Silver Grains
PT&PD Grains
WIre sheet tubing
New Products
United's certification
space
slogan
space
space space space
  2  
space Shrinkage Porosity Problem !  
space

Shrinkage porosity (dendritic porosity) is usually angular in shape, can be large or small and is
usually seen in patches in the heavier areas of the castings.
Please check:

1. Check the sprue placement on the casting. Sprues should be placed on the heaviest area of
the casting to allow progressive solidification of the metal.
2. Check the size of the sprues on the castings; they may be undersize for the size and weight
of the casting.
3. Avoid pinched sprues or narrowing of the sprues at the attachment areas of the casting.
This is a very common cause of shrinkage porosity.
4. Check the size of the main sprue rod on the cast trees; it may be too small for the size of the
tree being cast. The main sprue rod is a reservoir of fresh metal and heat to feed the castings
as they solidify.
5. Check the flask temperature being used; it may be too hot for the size and weight of the pieces being cast.
6. Multiple sprues may be needed on some delicate or thick – thin– thick designs to provide
a better feed and avoid shrinkage porosity.

 

 
space    
Backspace
space
space
467/7, 2nd Floor, Mahatun Rama 3 center, Rama 3 road, Bangkok 10120 Tel. (662) 2921992-3
line
467/7, ชั้น 2 โครงการมหาทุน พระราม 3 เซ็นเตอร์ ถนนพระรามที่ 3 กทม. 10120 Tel. (662) 2921992-3

Copyright 2012 United PM (Thailand) Co.,Ltd
space