Increased Shape Stability and Porosity of Highly Porous Injection‐Molded Titanium Parts1. Issue 11 (8th April 2015)

• Record Type: Journal Article
• Authors: Laptev, Alexander M.; Daudt, Natália F.; Guillon, Olivier; Bram, Martin
• Is Part Of: Advanced engineering materials. Volume 17:Issue 11(2015:Nov.)
• Page Start: 1579
• Page End: 1587
• Publication Date: 2015-04-08
• Subjects: Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.201500061
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : Highly porous titanium parts in three different shapes (conical, cylindrical, and semi‐cylindrical) were produced using metal injection molding (MIM) and the space holder technique. Potassium chloride (KCl) powder was used as a temporary space holder material. The frequently used extraction of the KCl space holder by dissolution in warm water was replaced with sublimation from the solid state during vacuum sintering. This improvement enabled highly porous titanium parts to be manufactured by MIM without the frequently observed sample collapse or extensive shape distortion. Final porosities of 55–60% were achieved, which is close to the recommended value for porous spinal titanium implants, making improved method attractive for implant manufacturing applications. An additional advantage of removing the space holder by sublimation is that the time‐consuming salt leaching step can be omitted. A systematic study of sample configuration, porosity change, microstructure, and impurity uptake was conducted and the sintering cycle was optimized. Abstract : Highly porous titanium parts are produced by metal injection molding and the space holder technique. The dissolution of the KCl space holder in water is replaced with sublimation during vacuum sintering. This improvement enables titanium parts to be manufactured without sample collapse or shape distortion. Final porosities are close to the recommended value for spinal implants. The time‐consuming leaching step is also omitted.