[An experimental study on laser-welded dissimilar alloys in dentistry.].

PURPOSE

This study evaluated the mechanical properties and microstructure of the joints of laser-welded dissimilar alloys usually used in clinical nowadays.

METHODS

The dissimilar alloys for Co-Cr alloy,Ni-Cr alloy and pure titanium were laser-welded. The joints were tested for the ultimate tensile strength (UTS) and the ultimate bending strength (UBS). The tensile fracture surfaces were examined by scanning electron microscopy (SEM). Metallurgical analysis was also performed on polished longitudinal sectioned samples.

RESULTS

Laser-welded dissimilar alloys between Co-Cr and Ni-Cr alloy can yield satisfactory mechanical properties, and there was no significant difference of UTS and UBS between Co-Cr welding wire group and Ni-Cr welding wire group (P>0.05). The laser-welded joints for dissimilar metal of pure titanium and Co-Cr,pure titanium and Ni-Cr, showed more brittle characteristics and severe defects (pores and cracks).

CONCLUSIONS

With Co-Cr or Ni-Cr welding wire, the laser-welded dissimilar alloys of Co-Cr alloy and Ni-Cr alloy can yield satisfactory joints. But pure titanium and Co-Cr alloy, pure titanium and Ni-Cr alloy cannot be directly melted together.