Wear Behavior and Machining Performance of TiAlSiN-Coated Tools Obtained by dc MS and HiPIMS: A Comparative Study.

Vitor F C Sousa,Rafaela C B Casais,Ricardo Alexandre,Francisco J G Silva,Andresa Baptista,Gustavo Pinto,Hernâni Lopes

doi:10.3390/ma14185122

Abstract

Duplex stainless steels are being used on applications that require high corrosion resistance and excellent mechanical properties, such as the naval and oil-gas exploration industry. The components employed in these industries are usually obtained by machining; however, these alloys have low machinability when compared to conventional stainless steels, usually requiring the employment of tool coatings. In the present work, a comparative study of TiAlSiN coating performance obtained by these two techniques in the milling of duplex stainless-steel alloy LDX 2101 was carried out. These coatings were obtained by the conventional direct current magnetron sputtering (dc MS) and the novel high power impulse magnetron sputtering (HiPIMS). The coatings were analyzed and characterized, determining mechanical properties for both coatings, registering slightly higher mechanical properties for the HiPIMS-obtained coating. Machining tests were performed with varying cutting length and feed-rate, while maintaining constant values for axial and radial depth of cut and cutting speed. The surface roughness of the material after machining was assessed, as well as the wear sustained by each of the tool types, identifying the wear mechanisms and behavior of these tools, as well as registering the flank wear values presented for each of the tested tools. The HiPIMS-obtained coating exhibited a very similar behavior when compared to the other, producing similar surface roughness quality. However, the HiPIMS coating exhibited less wear for higher cutting lengths, proving to be a better choice in this case, especially regarding tool life.

Highlights

By combining both the benefits of having α- ferrite and γ-austenite phases, Duplex Stainless-Steels (DSS) present excellent mechanical and corrosion resistance properties, making them a very appealing material [1]
The surface roughness values obtained for both directions and coated tools can be observed in Figures 2 and 3, as bar graphs, enabling their comparison
The high power impulse magnetron sputtering (HiPIMS)-obtained coated tools exhibited better results, both in terms of produced machined surface quality and sustained wear, especially for the tests conducted at 4 m cutting length;

Summary

Introduction

By combining both the benefits of having α- ferrite and γ-austenite phases, Duplex Stainless-Steels (DSS) present excellent mechanical and corrosion resistance properties, making them a very appealing material [1]. The authors defined the control factors as being depth of cut, feed rate, and spindle speed, concluding that the latter was the most influential parameter on the machined surface finish quality. The optimal cutting parameters for the best machined surface roughness were defined, highlighting that, for this material, the lowest surface roughness value was obtained for high cutting speeds and low feed rates. This conclusion was reached by Policena et al [14], where the authors perform end-milling finishing operations on DSS alloy, UNS S32205

Methods

Results

Conclusion