Technical Journal, Vol. 14 No. 4, 2020.
Original scientific paper
https://doi.org/10.31803/tg-20191028112617
The Effect of the Holding Pressure Profile on the Metal Injection Molded Component Dimensions after Sintering
Emir Šarić
orcid.org/0000-0003-0992-9716
; University of Tuzla, Faculty of Mechanical Engineering, Univerzitetska 4, 75000 Tuzla, Bosnia and Herzegovina
Samir Butković
; University of Tuzla, Faculty of Mechanical Engineering, Univerzitetska 4, 75000 Tuzla, Bosnia and Herzegovina
Muhamed Mehmedović
; University of Tuzla, Faculty of Mechanical Engineering, Univerzitetska 4, 75000 Tuzla, Bosnia and Herzegovina
Abstract
The volumetric flow rate (injection velocity) and the holding pressure are metal injection molding (MIM) parameters that have a strong influence on the green parts density and density homogeneity, but their effect on sintered dimensions after sintering is still to a large extent unexplored. To reveal the relationship between the injection molding parameters and sintered dimensions, ring-shaped components were injection molded by using different values of injection velocities in combination with a rump-down and rump-up holding pressure profile. Afterwards, the green components were catalytically debound and sintered in the nitrogen (N2) atmosphere. Finally, the component dimensions: the height, inner and outer diameter were measured by using a coordinate measuring machine. The ready-to-mold granules Catamold 310N made of heat resistant stainless steel X40CrNiSi 25-20 (according to the EN standard) powder and polyacetal based binder were used. The results showed that the interaction between the injection velocity and the holding pressure profile can be used to systematically adjust shrinkage after sintering. This approach is based on the dependence of the binder crystallization temperature on pressure, when the powder/binder proportion changes with the injection velocity.
Keywords
dimensional control; holding pressure profile; metal injection molding; shrinkage
Hrčak ID:
247400
URI
Publication date:
9.12.2020.
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