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 rumpup 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.
Highlights
metal injection molding (MIM) has been recognized as a technology for net shape production of small metallic components with complexity that can be achieved by injection molding techniques
To compare the results obtained by using different holding pressure profiles, the means with the ± standard deviation (SD) for the part width, inner and outer diameter after sintering vs. the injection velocity were plotted on bar graphs
The results showed that the average dimensions after sintering were positively correlated with the injection velocity when the rump-down holding pressure was used
Summary
MIM has been recognized as a technology for net shape production of small metallic components with complexity that can be achieved by injection molding techniques. The injection velocity and the holding pressure are the most important parameters of the injection molding phase for the dimensional precision of the final MIM components [5, 6]. Owing to the feedstock sensitivity to the injection, parameters’ change and the complex interconnection between the technological phases, the influence of injection parameters in the final part quality in MIM remain to a large extent an unexplored territory. With this motivation in mind, the current paper researches the interactive effects of the holding pressure profile and the volumetric flow rate (injection velocity) on the final dimensions’ change
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
