General problems encountered in Casting – Casting Defects:
Cracks: These are often related to the pressing cycle. Cracks are generally formed when the entrapped air expands. Cracks may be visible just after shaping process or may become visible even after firing. Thus cracks formed during firing could also be due to the shaping problem. To prevent the cracks, it is necessary to ensure that proper gatings are provided for easy release of the entrapped gases and better slip pouring mechanism is followed to prevent large voids.
Laminations: These are nothing but cracks that occurs in ceramic wares formed by extrusion process. These are formed due to improper re-knitting of the input material. Cracks in extrusion process can also be caused due to improper die design or due to low plasticity of the input material.
To be contd…
