Crazing Defect in MIM Process

Powder injection molding manufacture notes crazing  is a common defect in MIM process. Let’ probe into the reason for crazing defect based on past MIM parts experience.

When feedstock flows in mould,  the material near mould wall cool down faster than central hot melt interface, which will form shear stress for the central  hot melt interface, therefore crack occurs .

The causes and treatment:
- low quality mould , draft angle is insufficient
- too strong injection pressure or holding time is too long
- mold temperature is too low
- finished products cling to mould surface in vacuum status
- bad inserts design, or temperature is too low
- poor finished product design, change thickness greatly or  acute Angle

Original article link：http://www.zcmim.com/article/crazingdefectinmimprocess_1.html