Direct Laser Metal Deposition of AISI H13 Cladding on Copper–Beryllium Alloy Substrate Through a Stainless-Steel Buffer Layer Strategy

Abstract

AISI H13 cladding is deposited on the copper–beryllium (CuBe) alloy substrate by direct laser metal deposition via a buffer layer strategy. The SS316L austenite stainless steel is used as the buffer material attempting to reduce the risk of cracking. Single- and multi-layer samples are deposited, including single-layer SS316L, 1-layer SS316L + 1-layer H13, 2-layers SS316L + 1-layer H13, and 1-layer SS316L + 4-layers H13. The defect-free single-layer SS316L cladding is successfully deposited after the parameter pre-optimization. Two types of defects including porosity and cracking are observed in all multi-layer systems. The cladding microhardness of the 2-layer system is rather low (400HV). A 50% increase in the cladding microhardness is observed when depositing on the five-layer system. The five-layer system shows a better load-bearing capability (LBC) compared with the CuBe substrate in the low loading range. As load increases above 10 kN, the five-layer cladding system shows the worse LBC compared to CuBe due to the low strength of the heat-affected zone. A 2.7% cladding to substrate thickness ratio allows keeping more than 80% of the original thermal conductivity of the CuBe substrate.