Abstract
Structure, properties and serviceability of components made by wire arc additive manufacturing (WAAM) depend on the process parameters such as arc power, travel speed, wire diameter and wire feed rate. However, the selection of appropriate processing conditions to fabricate defect free and structurally sound components by trial and error is expensive and time consuming. Here we develop, test and utilize a three-dimensional heat transfer and fluid flow model of WAAM to calculate temperature and velocity fields, deposit shape and size, cooling rates and solidification parameters. The calculated fusion zone geometries and cooling rates for various arc power and travel speed and thermal cycles considering convective flow of molten metal agreed well with the corresponding experimental data for H13 tool steel deposits. It was found that convection is the main mechanism of heat transfer inside the molten pool. Faster travel speed enhanced the cooling rate but reduced the ratio of temperature gradient to solidification growth rate indicating increased instability of plane front solidification of components. Higher deposition rates could be achieved by increasing the heat input, using thicker wires and rapid wire feeding.
| Original language | English |
|---|---|
| Pages (from-to) | 1084-1094 |
| Number of pages | 11 |
| Journal | International Journal of Heat and Mass Transfer |
| Volume | 127 |
| DOIs | |
| State | Published - Dec 2018 |
| Externally published | Yes |
Funding
The authors gratefully acknowledge a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD) and the financial support of the Fundamental Research Funds for the Central Universities NP2016204 . One of the authors (T.M.) acknowledges support of an American Welding Society research fellowship , grant number 179466 .
Keywords
- Cooling rates
- H13 tool steel
- Heat transfer and fluid flow
- Solidification parameters
- Wire arc additive manufacturing
