Effect of Cryogenics-Assisted Low-Plasticity Burnishing on Laser-Clad Stellite 6 over SS420 Substrate
- PDF / 5,470,538 Bytes
- 9 Pages / 593.972 x 792 pts Page_size
- 55 Downloads / 150 Views
ASM International 1059-9495/$19.00
Effect of Cryogenics-Assisted Low-Plasticity Burnishing on Laser-Clad Stellite 6 over SS420 Substrate P. Vijay Anirudh, Bharath Kumar, Goutham Girish, S. Shailesh, R. Oyyaravelu, C. Kannan, and A.S.S. Balan (Submitted May 15, 2020; in revised form August 5, 2020; Accepted: 5 September 2020) The influence of modern additive manufacturing methods, especially from the direct energy deposition (DED) processes to the coat-like finished components, is crucial under present industrial circumstances. DED induces several traits like enhanced mechanical, thermal properties in shorter lead time, which extend their adaptation for diverse applications including aerospace and automobile industries. Among the several DED processes, laser cladding has been a prospect that explores various capabilities of improving the wear resistance of cobalt-chromium (Co-Cr)-based alloys. Rather than fabricating the complete component using expensive alloys, laser cladding has paved an approach to deposit particles possessing superior qualities over the conventional material. This research work attempts to evaluate the surface integrity of SS420 when cladded with Stellite 6. The vertical face milling is executed on the cladded component surface to facilitate either low-plasticity burnishing (LPB) or cryogenic burnishing (CB) as sequential post-treatment processes. The effects of these post-treatments on the surface and subsurface microhardness, surface topography and residual stress profiles are elaborated. Increased surface and subsurface microhardness, as well as improved residual stress profiles, are observed with CB over LPB-processed specimen samples. Keywords
cryogenic burnishing, direct energy deposition, laser cladding, microhardness, residual stress, Stellite 6
1. Introduction The emergence of tribology designates the materials according to their wear generation when exposed to severe conditions that eventually results in the degradation of mechanical properties. Wear is one of several life-limiting aspects of manufactured components, which results in high friction at elevated temperatures (Ref 1). Stellite 6, a high-performance cobalt-chromium alloy, has improved corrosion and wear resistance at high temperatures. Moreover, the meliorated hot hardness of this material increases the chances of being used in aerospace, mining and automobile industries (Ref 2, 3). Aerospace components such as turbine blades are operated under tight tolerance and fit and exposed to severe corrosion and wear during their service life. The main alloying constituents of Stellite 6, viz. chromium, tungsten and carbon, contribute significantly to their beneficial characteristics (Ref 4). Cobalt, being the principal constituent, reduces the hardenability of the component but retains the hardness after the heat treatment process, and chromium, the primary alloying element, increases the corrosion and wear resistance (Ref 5). The other alloying constituents include refractory elements like Mo and C, which improves the integrity of t
Data Loading...
