Effects of the Amount of Ti Addition on Sintering and Strength of 18Ni Maraging Steel Obtained by Powder Injection Molding Process Using a Mixture of Elemental Powders

Abstract

The 18Ni maraging steel is prepared by powder injection molding (PIM) process using a mixture of elemental powders with much attention to the effects of the amount of Ti addition on the flexure strength. Titanium, one of the components of the maraging steel makes it possible to precipitate the Ni₃Ti particles and to accelerate the precipitation of Ni₃Mo in a martensitic matrix of the steel on aging. X-ray diffraction confirms that the homogeneous alloying of all elements was completed at a relatively low temperature of 1473K, nevertheless sintering temperatures over 1563K were needed to obtain the PIM compacts with more than 95% for the relative density. The high density and strength in the PIM maraging steel is obtained at the Ti addition of 1.0 mass%.