Abstract
In this paper, a method of forming hard, wide-area, crack-free, and wear-resistant nitrided cases on commercially-pure titanium using a 3.5 kW CO2 laser-sustained plasma is described. This surface hardening method was comprised of two steps: (1) a laser-sustained nitrogen plasma was first used to nitride the titanium substrate; and (2) a laser-sustained argon plasma was then employed to remelt the nitrided layer deposited in the first step. Previous research using single laser trail experiments had shown that the (second) remelting step can eliminate cracks formed during the (first) nitriding step and homogenize the nitrided layer. In this work, the two-step nitriding-remelting process was extended to wider surface areas by depositing multiple overlapping trails at four different nitriding speeds and a constant remelting speed. The hardened layer was characterized using x-ray diffraction (XRD), optical metallography, and hardness testing. Reciprocating ball-on-flat wear tests were conducted to assess the wear resistance of the nitrided case, with the wear scar being characterized using scanning electron microscopy (SEM) and optical profilometry. Crack-free, hard cases of depths up to 600 μm and average hardness values up to 641 ± 86 HV0.3 were observed. The LSP nitriding-remelting treatment was found to improve the wear resistance of the base metal (CP-Ti) by up to 80%.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 229-238 |
| Number of pages | 10 |
| Journal | Surface and Coatings Technology |
| Volume | 325 |
| DOIs | |
| State | Published - Sep 25 2017 |
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All Science Journal Classification (ASJC) codes
- Chemistry(all)
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry
Cite this
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Enhancement of CP-titanum wear resistance using a two-step CO2 laser-sustained plasma nitriding process. / Kamat, Amar M.; Segall, Albert Eliot; Copley, Stephen M.; Todd Copley, Judith.
In: Surface and Coatings Technology, Vol. 325, 25.09.2017, p. 229-238.Research output: Contribution to journal › Article
TY - JOUR
T1 - Enhancement of CP-titanum wear resistance using a two-step CO2 laser-sustained plasma nitriding process
AU - Kamat, Amar M.
AU - Segall, Albert Eliot
AU - Copley, Stephen M.
AU - Todd Copley, Judith
PY - 2017/9/25
Y1 - 2017/9/25
N2 - In this paper, a method of forming hard, wide-area, crack-free, and wear-resistant nitrided cases on commercially-pure titanium using a 3.5 kW CO2 laser-sustained plasma is described. This surface hardening method was comprised of two steps: (1) a laser-sustained nitrogen plasma was first used to nitride the titanium substrate; and (2) a laser-sustained argon plasma was then employed to remelt the nitrided layer deposited in the first step. Previous research using single laser trail experiments had shown that the (second) remelting step can eliminate cracks formed during the (first) nitriding step and homogenize the nitrided layer. In this work, the two-step nitriding-remelting process was extended to wider surface areas by depositing multiple overlapping trails at four different nitriding speeds and a constant remelting speed. The hardened layer was characterized using x-ray diffraction (XRD), optical metallography, and hardness testing. Reciprocating ball-on-flat wear tests were conducted to assess the wear resistance of the nitrided case, with the wear scar being characterized using scanning electron microscopy (SEM) and optical profilometry. Crack-free, hard cases of depths up to 600 μm and average hardness values up to 641 ± 86 HV0.3 were observed. The LSP nitriding-remelting treatment was found to improve the wear resistance of the base metal (CP-Ti) by up to 80%.
AB - In this paper, a method of forming hard, wide-area, crack-free, and wear-resistant nitrided cases on commercially-pure titanium using a 3.5 kW CO2 laser-sustained plasma is described. This surface hardening method was comprised of two steps: (1) a laser-sustained nitrogen plasma was first used to nitride the titanium substrate; and (2) a laser-sustained argon plasma was then employed to remelt the nitrided layer deposited in the first step. Previous research using single laser trail experiments had shown that the (second) remelting step can eliminate cracks formed during the (first) nitriding step and homogenize the nitrided layer. In this work, the two-step nitriding-remelting process was extended to wider surface areas by depositing multiple overlapping trails at four different nitriding speeds and a constant remelting speed. The hardened layer was characterized using x-ray diffraction (XRD), optical metallography, and hardness testing. Reciprocating ball-on-flat wear tests were conducted to assess the wear resistance of the nitrided case, with the wear scar being characterized using scanning electron microscopy (SEM) and optical profilometry. Crack-free, hard cases of depths up to 600 μm and average hardness values up to 641 ± 86 HV0.3 were observed. The LSP nitriding-remelting treatment was found to improve the wear resistance of the base metal (CP-Ti) by up to 80%.
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U2 - 10.1016/j.surfcoat.2017.06.030
DO - 10.1016/j.surfcoat.2017.06.030
M3 - Article
AN - SCOPUS:85021349677
VL - 325
SP - 229
EP - 238
JO - Surface and Coatings Technology
JF - Surface and Coatings Technology
SN - 0257-8972
ER -