The Effect of Scanning Strategies on Geometrical Accuracy & Surface Roughness of H13 Tool Steel Parts in Laser Powder Bed Fusion Process
Typ
Examensarbete för masterexamen
Program
Product development (MPPDE), MSc
Publicerad
2019
Författare
Ashok Kumar, Rajendran
Ahmadnia Feizabadi, Masoud
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Additive Manufacturing (AM) combined with the development of new materials and
the current available processes, has the potential to revolutionize the way of manufacturing
products. Making parts with higher geometrical precision and better surface
finish will pace up this revolution. In this project the effect of scanning strategies
on geometrical accuracy and surface roughness of parts made of H13 tool steel via
SLM process is investigated. A raster scanning pattern with 3 different hatch rotation
angles(10, 67 and 180 degrees) were implemented. The effect of contouring was
also studied by comparing the results from contoured and non-contoured samples.
The results show that the 10 degree hatch rotation angle causes less deviation even
though 67 degree is commonly mentioned as the optimum hatch rotation angle in
most of the research papers. The surface roughness in parts printed without the
contouring step is of poorer quality than the ones with contouring. Irrespective of
employing this contouring step or not, a post-processing step like milling or grinding
is required to achieve the desired surface roughness. Therefore, it can be suggested
to skip contouring in order to save printing time. However, in terms of achieving the
best geometrical accuracy, it is recommended that the contouring step is employed
for printing thin wall of 0.5mm thick.
Beskrivning
Ämne/nyckelord
SLM, Geometry Assurance, Surface Roughness, Scanning Strategy, Contouring , Hatch Rotation Angle