Effect of surface roughness on quality perception of Laser Sintered (LS) parts

Additive Manufacturing (AM) is a revolutionary technology that in recent years has become increasingly visible in mainstream media and is in the process of being developed for more widespread industrial applications. One of the challenges that has hindered the growth of AM in industry has been the aspect of surface finish, particularly in the use of Laser Sintering (LS). The surfaces produced are often perceived to be of a lower quality than those of other more traditional techniques. One of the ways in which developments have been made to address this issue is to use different post-processing techniques to achieve a variety of surface finishes. These decisions are often made by the machine manufacturers and researchers without any input from the product consumers.

This thesis aims to include the consumer in the surface finish decision-making process. The main focus is to investigate the consumer perceptions of different LS surface finishes and roughness through the utilization and adaptation of human interaction and social science techniques.

A group of 44 participants performed a number of blind trials on different roughness parts. It was found that up to a certain point a decrease in roughness led to a growth in perceived quality, but this increase was not infinite. All users identified roughness and smoothness as directly relating to quality; whilst other vocabulary was used to describe quality, these did not translate to “real” effects during testing.

Crucially 50% of participants’ opinions of quality changed when allowed to perform a visual assessment of the parts.