# Performance of Laser-Clad Transition Layers on H13 Steel

## TL;DR

This paper finds that Inconel 718 is the best transition layer material for laser cladding CoCrFeNiAl high-entropy alloy onto H13 steel, as it prevents cracks and improves performance under stress.

## Contribution

The study identifies Inconel 718 as the optimal transition layer material for laser cladding on H13 steel, based on mechanical testing.

## Key findings

- Inconel 718 transition layers prevented cracks during bending tests.
- Inconel 718 showed high yield strength and resistance to plastic deformation in hot tensile tests.
- Other alloys like FGH4096 and FGH4169 failed due to poor diffusion and bonding.

## Abstract

This study addresses the crack formation problem when laser cladding CoCrFeNiAl high-entropy alloy onto H13 hot-work die steel, aiming to identify suitable transition layer materials. Five nickel-based alloys—Inconel 718, Inconel 625, Hastelloy X, FGH4096, and FGH4169—are selected as alternatives. Three-point bending and hot tensile tests are conducted to assess performance under different stress directions. Test results show that the FGH4096 and FGH4169 coatings fail due to insufficient element diffusion and weak interfacial bonding. Cracks appear at the coating–substrate interface of Inconel 625 and Hastelloy X. In contrast, Inconel 718 performs best, with excellent thermal expansion matching and strong stress resistance. In the three-point bending test, the specimens with Inconel 718 transition layers did not show cracks during the loading process, while specimens with some other alloy transition layers cracked or fractured, which proves that Inconel 718 can effectively enhance the bonding force between the coating and the substrate and improve the material’s performance under bending stress. In the hot tensile test, the stress–strain curve of Inconel 718 is at a high position with a high yield strength, showing excellent resistance to plastic deformation and significantly improving the performance of the nickel-based layer under hot tensile conditions. Therefore, Inconel 718 is identified as the optimal transition layer material.