Abstract:

BACKGROUND: There are no reports on laser welding about a kind of Co-Cr alloys, which do not include Ni and Be nowadays.
OBJECTIVE: To apply laser welding technique to prepare a new Co-Cr alloy in order to provide welding parameters for clinic application.
METHODS: Sixty plastic plate patterns (0.5 mm×6 mm×30 mm) were casted from new Co-Cr alloy. All the plates were randomly divided into 6 groups, one as control group, and the others as examination group. The plates of examination group were perpendicularly cut at the center of the plates. After the cut halves were fixed in a jig, they were laser welded using a NG:YAG laser at a several level output energy in increments of 30 V from 220 to 340 V. The spot diameter and pulse duration employed was 0.6 mm and 10 ms. Uncut specimens served as the non-welded control specimens. Tensile testing was conducted and the breaking force was recorded and the data was statistically analyzed. 
RESULTS AND CONCLUSION: The tensile strength of laser welding New Co-Cr alloys increased with the electric voltage. The elongation increased with the electric voltage at the electric voltage lower than 280 V, but showed contrary trend when the electric voltage higher than 280 V. The tensile strength and elongation was (679.94±46.87) MPa and (5.91±0.38)% respectively at the optimized welding parameters. The tensile strength and elongation of laser welded New Co-Cr alloy under the optimized parameters (280 V, 10 ms, spot diameter 0.6 mm) can be satisfied with the clinical requirement.