Transverse Strength and Microstructure of Cobalt-Chromium Alloy Produced By Selective Laser Melting and Casting Techniques(An in vitro study)
Author(s): Abbas Hamad Ghadhban* and Ibtehal Hazim Hasan
Aim: Investigate the differences between the transverse strength and microstructures of specimens produced by two techniques, the conventional casting technique and selective laser melting technique.
Materials and methods: Co-Cr alloy specimens are manufactured by two different techniques; conventional casting of resin pattern, selective laser melting techniques. Each technique was used to manufacture twelve specimens, making a total of twenty four. Each group was used for testing transverse strength. Two specimens of each group of transverse are used for a scanning electron microscope to show the fractured and non-fractured side microstructure. Differences in transverse strength were statistically analyzed by using the independent sample T-test.
Results: Transverse strength of the selective laser melting specimens had a significantly higher value compared to casting specimens. Scanning electronic microscope revealed casting group displayed inhomogeneous grain size (20-100) micrometer while laser group shows homogeneous grain size (2-20) micrometer.
Conclusion: As laser has a better transverse strength than casting, scanning electron microscope displays fine crystalline structure while casting has big crystalline features.