Abstract
This work reports the results of our investigation of the structure and mechanical properties of physical vapor deposition (PVD) and chemical vapor deposition (CVD) TiAlSiN coatings deposited on cemented carbide substrates. For the first time, a novel nanocomposite of Ti0.13Al0.85Si0.02N coating deposited from TiCl4-AlCl3-SiCl4-NH3-H2 gas precursors was prepared by low pressure chemical vapor deposition (LPCVD) at 780 °C and a pressure of 60 mbar, while PVD Ti0.31Al0.60Si0.09N coating was prepared using the arc ion plating method. The investigation results including morphology, microstructure, chemical composition, phase component, and hardness were carried out by scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), and nano-indentator. TEM results revealed that both PVD and CVD TiAlSiN coatings consisted of nanocrystalline embedded in SiNx amorphous. The nanohardness of CVD Ti0.13Al0.85Si0.02N coating obtained in this work was 31.7 ± 1.4 GPa, which was 35% higher than that of the PVD Ti0.31Al0.60Si0.09N coating.
Highlights
With the increasing demands for materials used in dry and high speed cutting and machining in the metalworking industry, it is imperative to develop a coated cemented carbide cutting tool with improved performance
For the chemical vapor deposition (CVD) TiAlSiN coating, it was reasonable to detect a small amount of Cl in the coating due to the low deposition pressure and three chlorides TiCl4AlCl3-SiCl4 contained in the gaseous mixture
We found that the element Co was distributed into the first layer, which is caused by the high deposition temperature of CVD method and the rapid diffusion of Co
Summary
With the increasing demands for materials used in dry and high speed cutting and machining in the metalworking industry, it is imperative to develop a coated cemented carbide cutting tool with improved performance. As a traditional hard coating, TiN single layer coating has been widely used due to the similar thermal expansion coefficient with high speed steel tools. Much attention was recently paid to the development of TiSiN coating, which consists of nano-crystalline TiN and amorphous SiNx with high physical and mechanical properties, such as superhardness (>40 GPa), high oxidation resistance (around 850 ◦C), and high thermal stability (up to 1100 ◦C) [7,8,9,10]. Qiu et al [11] reported that the
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