Influence of High-Temperature Substrate Preheating on Laser Cladding of Stellite 6 onto Inconel 718 Alloy

Area of Science:

• Materials Science
• Surface Engineering
• Additive Manufacturing

Background:

• Laser cladding is vital for component repair and wear resistance.
• High substrate temperatures can negatively impact cladding quality, especially on alloys like Inconel 718.
• Controlling heat dissipation is crucial for successful cladding of components like turbine blades.

Purpose of the Study:

• To investigate the influence of substrate temperature on laser cladding of Stellite 6 onto Inconel 718.
• To analyze the effects on single track geometry, microstructure, and hardness.
• To determine optimal laser cladding parameters considering substrate preheating.

Main Methods:

• Laser cladding using Stellite 6 powder and an Yb:YAG laser.
• Substrate preheating to temperatures between 20 °C and 800 °C.
• Analysis of track geometry, dilution, microstructure (SEM), and hardness (HV0.3).

Main Results:

• Elevated substrate temperatures widened the melt pool and increased melt depth.
• Track height remained largely unchanged, but dilution exceeded 35% at higher temperatures.
• Hardness decreased to Inconel 718 substrate levels (395 HV0.3) due to excessive dilution.

Conclusions:

• Substrate temperature significantly affects laser cladding geometry and dilution.
• High preheating temperatures are detrimental to achieving a hard, low-dilution Stellite 6 cladding on Inconel 718.
• Careful control of substrate temperature is essential for effective surface protection via laser cladding.