MIM tips for designers
December 14, 2022

Manufacturing / Corner

Manufacturing / Corner

Before

Compared with plastic injection moulding, the material or feedstock of MIM is brittle.

Therefore, it is more likely to occurred crack in demoulding process especially at the sharp edge corner.

This sharp edge corner is not only causing the crack but also inhomogeneous metal powder distribution and this leads poor mechanical property.

After

Apply curve or chamfered corner to avoid demoulding or inhomogeneous problems.

Conclusion

Cracking, slumping or blistering is commonly observed due to the binder swelling and/or residual stress difference between the surface and interior. It is possible to avoid these problems by selecting appropriate organic solvents and temperature control.

The catalytic deboning uses sublimation of binder, thus it is possible to decompose the binder in relatively short processing time with minimizing the deformation. However, with a strong acidic atmosphere, theapplicable metal material option is limited.

In the sintering process, the necking, which is bridging the metal powders by thermal diffusion, starts at the sintering temperature. Once the necking starts, the shrinking is observed and increases the density, thus before starting the necking reaction, all the organic components should be decomposed and gas between the powders should be removed. In the sintering process, the unwanted chemical reaction, such as oxidation or carbonization, leads to mechanical property loss, therefore a precise atmosphere control with low heating rate at the beginning of the process is required. Also, when it reaches the sintering temperature, some add it vegetal can be evaporated.

Share this post

Related posts

Manufacturing / Thickness Pt. 2
MIM tips for designers
December 14, 2022

Manufacturing / Thickness Pt. 2

Either eliminating the sudden huge thickness change or giving curve at the corner will minimise the problems above mentioned.
Read more
Manufacturing / Undercut and internal curve design
MIM tips for designers
December 14, 2022

Manufacturing / Undercut and internal curve design

Applying our 3D-MIM technology, it is possible to mass produce complex hollow design or micro size configuration.
Read more
Manufacturing / Gate treatment Pt. 1
MIM tips for designers
December 14, 2022

Manufacturing / Gate treatment Pt. 1

Apply higher level of gate will minimise the polishing amount.
Read more