Analysis of Microstructure and Properties of a Ti–AlN Composite Produced by Selective Laser Melting

Abstract

Selective Laser Melting (SLM) is a manufacturing technique that is currently used for the production of functional parts that are difficult to form by the traditional methods such as casting or CNC (Computer Numerical Control) cutting from a wide range of metallic materials. In our study, a mixture of commercially pure titanium (Ti) and 15% at. aluminum nitride (AlN) was Selective Laser Melted to form three-dimensional objects. The obtained 4 mm edge cubes with an energy density that varied from 70 to 140 J/mm3 were examined in terms of their microstructure, chemical and phase composition, porosity, and Vickers microhardness. Scanning Electron Microscopy (SEM) observations of the etched samples showed inhomogeneities in the form of pores and unmelted and partly melted AlN particles in the fine-grained dendritic matrix, which is typical for titanium nitrides and titanium aluminum nitrides. The AlN particles remained unmelted in samples, but no porosity was observed in the interface area between them and the dendritic matrix. Additionally, samples fabricated with the presintering step had zones with different sizes of dendrites, suggesting a differing chemical composition of the matrix and the possibility of the formation of the phases forming an Ti–Al–N ternary system. The chemical composition in the microareas of the samples was determined using Energy Dispersive X-Ray Spectroscopy (EDS) and revealed differences in the homogeneity of the samples depending on the SLM process parameters and the additional presintering step. The phase composition, examined using X-ray Diffraction analysis (XRD), showed that samples were formed from Ti, TiN, and AlN phases. Porosity tests carried out using a computer microtomography revealed porosities in a range from 7% to 17.5%. The formed material was characterized by a relatively high hardness exceeding 700 HV0.2 over the entire cross-section, which depended on the manufacturing conditions.

Manufacturing of complex diamond-based composite structures via laser powder-bed fusion

“…1c [39]. Intuitively, micrometric particles altered the molten pool rheology, surface tension, and metal vapor density, as has been reported [7,40,41]. Also, a pronounced spattering phenomenon was observed when 5 vol.% coated -D was mixed with Cu compared to a pure Cu bed situation (Fig.…”

Composite Nitride Nanoceramics in the System Titanium Nitride (TiN)-Aluminum Nitride (AlN) through High Pressure and High Temperature Sintering of Synthesis-Mixed Nanocrystalline Powders

“…Somewhat related to the AlN-TiN system are attempts to make mixed metal-metal nitride ceramics as demonstrated by laser melting in the system Ti-AlN yielding composites with Vicker’s hardness of ca. 6.9 GPa [ 66 ]. The h-AlN/c-TiN nanoceramics in this study with hardness in the range 6.7–19.9 GPa span from rather good to very high hardness values.…”

Fabrication of Titanium and Copper-Coated Diamond/Copper Composites via Selective Laser Melting

“…Metal vapor-induced entrainment caused powder-spattering behavior [ 44 ]. To be intuitive, micrometric particles changed the surface tension, molten pool rheology, and metal vapor density according to declaration [ 45 , 46 , 47 ]. Also, it was believed that the imbalance of the molten pool, hot spatter collision during flight and entrained particles gathered on the solidified area were among the major driving forces for big spatter production.…”