Abstract
The alterations in the microhardness of a titanium alloy Ti85.85Al6.5Zr4Sn2Nb1Mo0.5Si0.15 subjected to laser treatment were investigated. Laser processing consists of a series of pulses with durations 20 ns. We used various methods of laser processing, which differed in power density, wavelength, geometrical pattern of irradiation and so on. The dependences of the microhardness on the load on the indenter were found. The laser processing modes providing the increased microhardness are determined. The investigations were carried out at loads from 0.49 N to 4.9 N, with maximum indentation depth of the Vickers pyramid up to 12 μm. Vickers microhardness can be increased by 20 – 40 %. At the same time, the plastic properties of the hardened layer are improved. The probability of crack formation during indentation of the initial alloy increased with a load on the indenter and reached 0.52 for a load of 4.9 N. In two of the treated areas of the three presented, crack formation was not recorded at any load. The mechanisms of hardening of the material surface layer under the influence of a laser pulse are discussed. Using the methods of computational mathematics, the character of sample heating under the influence of a single laser pulse is determined. The perspectives for the development of the proposed processing method are permitting to obtain the optimal mechanical properties of the hardened layer are discussed.
Highlights
The work of aircraft gas turbine engine parts occurs in harsh conditions and is accompanied by intense wear
The aim of this work is the experimental identification of the dependences of the microhardness on the load for various laser treatment modes, as well as determining the parameters of the laser processing, which provide a simultaneous increase in microhardness and crack resistance of the hardened surface layer
The third region has significant irregularities in the form of ditches and depressions. They are stretched along the laser processing lines (Figure 2)
Summary
The work of aircraft gas turbine engine parts occurs in harsh conditions and is accompanied by intense wear. Various hardening technologies have been developed for surface layers of parts [1,2,3] These technologies are aimed at increasing the surface microhardness, creating compressive stresses, increasing toughness, etc. In this case, both the depth of the hardened layer and its adhesion to the main material are of great importance. Both the depth of the hardened layer and its adhesion to the main material are of great importance The properties of the hardened layer should be free of cracking occurring at the boundary between the hardened material and the initial one
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
