Mechanical strength and analysis of fracture of titanium joining submitted to laser and tig welding

• Published in: Materials research (São Carlos, São Paulo, Brazil) Vol. 15; no. 6; pp. 937 - 943
• Main Authors: Piveta, Ana Cláudia Gabrielli, Montandon, Andréia Affonso Barreto, Ricci, Weber Adad, Nagle, Maurício Meirelles
• Format: Journal Article
• Language: English
• Published: ABM, ABC, ABPol 01.12.2012; Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímeros (ABPol)
• Subjects: dental welding; ENGINEERING, CHEMICAL; laser welding; MATERIALS SCIENCE, MULTIDISCIPLINARY; mechanical strength; METALLURGY & METALLURGICAL ENGINEERING; prosthesis implant; TIG welding; titanium; mechanical strength; TIG welding; prosthesis implant; laser welding; dental welding; titanium
• ISSN: 1516-1439; 1980-5373; 1980-5373
• DOI: 10.1590/S1516-14392012005000127

This study compared the tensile strength and fracture mechanism of tungsten inert gas (TIG) welds in cylindrical rods of commercially pure titanium (cp Ti) with those of laser welds and intact samples. Thirty dumbbell-shaped samples were developed by using brass rods as patterns. The samples were invested in casings, subjected to thermal cycles, and positioned in a plasma arc welding machine under argon atmosphere and vacuum, and titanium was injected under vacuum/pressure. The samples were X-rayed to detect possible welding flaws and randomly assigned to three groups to test the tensile strength and the fracture mechanism: intact, laser welding, and TIG welding. The tensile test results were investigated using ANOVA, which indicated that the samples were statistically similar. The fracture analysis showed that the cpTi samples subjected to laser welding exhibited brittle fracture and those subjected to TIG welding exhibited mixed brittle/ductile fracture with a predominance of ductile fracture with the presence of microcavities and cleavage areas. Intact samples presented the characteristic straightening in the fracture areas, indicating the ductility of the material.