Processing and characterization of porous titanium for implants by using NaCl as space holder

Mechanical and Corrosion Behavior of New Generation Ti-45Nb Porous Alloys Implant Devices

“…One of the concerns of using NaCl as a space-holder is its relatively low melting point of 801 • C. If the molten space-holder material can chemically react with an alloy, it may dissolve the alloy and can wet the alloy powders, thus preventing their densification [19]. According to a study by Bansiddhi et al [19], neither of this happens during the hot-pressing of TiNi alloy with NaCl space-holder at a temperature above 950 • C. Besides that, the shape of the pores after NaCl dissolution stays rectangular, replicating the actual shape of NaCl solid crystals [12,43,44]. The results of our experiments agree with this.…”

Open Celled Porous Titanium

“…Good water solubility & low cost [34][35][36][37][38] MIM+Space holder [35] 60 °C for more than 72 hrs [39] 50 °C for 40 hrs (92% removed) Warm compaction [36] 24 hrs (96% removed)…”

“…As well as the typically limited range of part geometries that can be created, a drawback of applying these techniques is that the pressures involved are high, and this can cause the space holder particles to deform and break during compaction, altering the final shape of the pores. For example, it has been reported that NaCl space holders are broken at a pressure higher than 350 MPa [34] , and it has been noted that the space holder particles are deformed and flattened in the direction of the applied pressure during HP, leading to flattened pores with deformed shapes [55] .…”

Open pore titanium foams via metal injection molding of metal powder with a space holder

“…Hence, many scholars have intensively investigated the use of the powder metallurgy with space holder technique for the production of Ti foams [12,14]. However, there are several challenges associated with such method that are yet to be solved; for instance the breakage and deformation of the space holder particles due to the high pressure applied (which leads to deformed pores), and the segregation of powders due to differences in densities [1,15]. One advanced powder processing technique with the potential to address these aforementioned issues, as well as offering the possibility of mass producing near net shaped Ti foams is Metal Injection Molding in combination with a Space Holder (MIM-SH).…”