Recent Studies of the Laser Cladding of High Entropy Alloys

Abstract

Trend of Metal 3D Printing by WeldingJae-Gyu Byun* and Sang-Myung Cho** , † *Dept. of Materials System Engineering, Graduate School, Pukyong National University, Busan 48513, Korea **Dept. of Materials System Engineering, Pukyong National University, Busan 48513, Korea † Corresponding author : pnwcho@pknu.ac.kr (Received June 14, 2016 ; Revised July 13, 2016 ; Accepted July 29, 2016) AbstractMetal AM(Additive Manufacturing) has been steadily developed and that is classified into two method. PBF(Powder Bed Fusion) deposited in the bed by the laser or electron beam as a heat source of the powder material and DED(Directed Energy Deposition) deposited by varied heat source of powder and solid filler material. In the developed countries has been applying high productivity process of solid filler metal based DED method to the aerospace and defense sectors. The price of the powder material is quite expensive compared to the solid filler metal. A study on DED method that is based on a solid filler metal is increasing significantly although was low accuracy and degree of freedom.

Gas tungsten arc weldability of stainless steel 304 using CoCrFeMnNi filler metals for cryogenic applications

“…The upper beads were nearly flat and the lower beads hung down to achieve a convex shape, regardless of the filler type. The CoCrFeMnNi HEA is known to have a melting temperature of 1270°C, which is lower than the melting temperature (1450°C) of STS 304 [35, 36]. Therefore, the CoCrFeMnNi filler provided an insufficient heating to allow fully melting of STS 304 BM.…”

Overview of the High-Entropy Alloys Concept

“…This process favors the strong adhesion of the coating to the substrate, homogeneous microstructure, and formation, but has less thermal damage caused by the fast heating and cooling rates involved in the process. The main disadvantages of laser doping of the surface are the formation of the peri-seam zone, high residual stresses and elemental dilution of the HEA coating and the substrate [101].…”

High Entropy Alloy Coatings and Technology

“…This process contributes to a strong coating substrate bonding, uniform microstructure, formation, but there is smaller thermal damage caused due to rapid heating and cooling rates involved in the process. The major drawbacks of laser surface alloying are the formation of the heat-affected zone, high residual stresses, and elemental dilution of the HEA coating and the substrate [49]. The manufacturing process of high entropy alloys affects their microstructure considerably.…”