Weldability of Grade 2 Titanium Sheets with Pulsed Nd:YAG Microlaser Welding Filler and Without Filler

Laser welding method is widely used in the welding of different materials. Deep penetration, low heat input, narrow heat affect zone, low stress-strain, and distortion are important features of this welding method as compared to other joint methods. Today, it is possible to see the applications of laser welding in the repair of precious metals, moulds, and machine parts. The laser welding method is preferred in the manufacture of many parts of precious metals. Titanium and particularly Grade 2 alloys are used in a wide range of applications, from medical applications to the aerospace industry applications. Since titanium is made of precious metals, it is of great use in manufacturing without much scrap. In the joints made by welding, it is estimated that the amount of scrap loss will decrease as a result of the potential to predict the distortion that the material will undergo and to provide more controlled planning of the current production. In this study, the weldability of 0.6 mm sheet materials with laser butt-welding was investigated. The effects of pulsed micro laser welding parameters on the microstructure, mechanical properties, and surface morphology of the fractures were investigated. As a result of the microstructure examination, it was found that cross-section narrowing was seen without filling welding. Fracture of the welded joints occurred in the base metal, showing an ultimate tensile strength of approximately 248 MPa with an elongation of 26.7 %.

Microstructural Characterization of the Laser Welding in a Nickel Based Superalloy

ABSTRACTIn this research it was experimentally analyzed the effect of the parameters of the Pulsed Micro Laser Welding Process Nd:YAG on the microstructural behavior of a nickel base superalloy (IN-738). For this purpose, different laser welding tests were performed on samples subjected to different heat treatment conditions obtained from the gas turbine blades. The influence of the power and the speed welding of the applied process and heat treatment condition on the weld geometry, microstructure and mechanical properties was determined. The microstructures of the obtained welds were characterized by scanning electron microscopy and Vickers hardness tests. In general, alternatives to homogenize and rejuvenate the microstructure of the base material are proposed in order to avoid the formation and propagation of cracks. The results are discussed mainly in terms of the present phases and decomposition of carbides, which considerably affect the weldability of the IN-738 superalloy. This study provides useful information for the subsequent restoration of the 2nd step turbine blades by using of the Laser Welding Process Nd:YAG.

Microstructure and Properties of 0.2mm Thick Sheet Titanium Alloy by Micro-Laser Welding

0.2mm thick titanium alloy sheet was butt-welded using micro impulse laser, influnce of the different processing parameter on the surface and cross-section morphology of welded joint was studied , testing the mechanical properties of joints. The result show that argon as a shielding gas, 0.2mm thick titanium alloy to the laser as heat source can be successful butt welding with process parameters of the pulse power 8.8W, pulse width 2.9ms, pulse frequency 7.0HZ, and forming a good welded appearance, the tensile strength and microhardness of welded joints was higher than the base metal. By the needle-like martensite α 'phase composition of the basket-like structure located in the center of the weld.