In this study, the effect of arc mode in cold metal transfer (CMT) process on the porosity characteristic of additively manufactured Al-6.3%Cu alloy has been systematically investigated. The variants include conventional CMT, CMT pulse (CMT-P), CMT advanced (CMT-ADV) and CMT pulse advanced (CMT-PADV) and experiments were performed on both single layer deposits and multilayer deposits. The mechanism of porosity generation using the CMT arc mode variants is discussed. It was found that deposit porosity is significantly influenced by the arc mode type of CMT process. Conventional CMT is not suitable for the additive manufacturing process because it produces a large amount of gas pores, even in single layer deposit. CMT-PADV proved to be the most suitable process for depositing aluminium alloy due to its excellent performance in controlling porosity. With correct parameter, setting the gas pores can be eliminated. It was found that the key factors that enable the CMT-PADV process to control the porosity efficiently are the low heat input, a fine equiaxed grain structure and effective oxide cleaning of the wire.

Effect of arc mode in cold metal transfer process on porosity of additively manufactured Al-6.3%Cu alloy

Although wire arc additive manufacturing (WAAM) has proven its capability of fulfilling demands of production of medium-to-large-scale components for automotive and allied sectors made up of alumin...

A review of wire arc additive manufacturing and advances in wire arc additive manufacturing of aluminium

Cold metal transfer (CMT) technology - An overview

Wire and arc additive manufacture enables us to build fully dense metallic parts by depositing material in layers using a welding process. Conventionally, in this process, the welding torch is always maintained in a vertical orientation, but this can cause accessibility problems and may require that the part is moved during the deposition process. The aim of the research presented in this article is to investigate the production of geometrical features using wire and arc additive manufacture with positional welding. Positional welding is particularly useful for building features with limited accessibility without having to manipulate the part. In the current work, inclined and horizontal wall features have been built using an inclined torch position. The knowledge obtained from these experiments has been further applied to build enclosed features. Additionally, a range of travel speeds has been investigated to better understand the effect of travel speed on part quality for angled walls. Factors that hind...

Fabrication of geometrical features using wire and arc additive manufacture

https://profdoc.um.ac.ir/articles/a/1055852.pdf

Craig Graeme Pickin

Papers

Characterisation of the cold metal transfer (CMT) process and its application for low dilution cladding