Did the metal powder be melted during the MIM injection process?
A: No,just only the binder be melted to make the metal powder flowed on the runner like the plastic material,the cool binder makes the injection parts be strong on some extent.After that,we would do debinding operation,it is able to remove 98% binder,so after that,the parts become more fragile.After the debinding,we would do high temperature sintering on it,it is able to remove the remaining 2% binder,after that,the parts get a high density and mechanical strength.
During the debinding process,would the part be shrinkaged?
A: No,the parts volume would not be shrinkaged after the debinding processing,but shrinkaged after the sintering process,shrinkage rate 16-20%.
How to choose the fine metal powder on Metal injection Molding process?
A: The ideal size of MIM metal powder is 2-8μm(powder particle size);loose packing density:40%-50%;tap density:above 50%,the shapes very close to ball shape.Now,the raw MIM metal powder including the iron powder,nickel powder,titanium powder,stainless steel powder,and super alloy powder,etc, meanwhile,many manufacturers are developing more new material,such as the structure material,function material and magnetic material,etc.
How to choose the good binder?
The plastic material POM in the plastic-based binder has no a good lubricating performance,eventhough under the melting condition,its viscosity is very high,so not good for the injection and demolding.The paraffin wax in the wax-based binder has a good lubricating performacne,but if the cooling temperature exceed the control point,then the injection parts shape could not be maintained.
