Microstructure Analysis of Welded Joints after Laser Welding

Abstract

Titanium alloys are widely used in aerospace and automotive industries. They are used to implement some parts of machines, also in the chemical industry, power industry, arms industry, shipbuilding, in implantology and biomedical engineering. Extent of use of this material is mainly due to high corrosion resistance, especially in aggressive environments. These are materials with a low ratio of the weight in relation to the mechanical properties. That is, while maintaining the desired mechanical properties of structures made of titanium is lighter than the standard stainless steel.Unfortunately, the properties of titanium, in particular at temperatures higher than the affinity of the nitrogen and oxygen in the air, has an effect on some types of processing. In particular, the heat treatment as cutting or welding, due to the fact that the reaction of titanium and oxygen is highly exothermic. Therefore, the parts of the titanium produced in an inert atmosphere.

Parametric optimisation of laser welding of stainless steel 316L

“…The laser power has a direct influence on the size of the heat affected zone, which can clearly be seen in the microstructure of the welded plates. Increasing the power density changes both the dimensions and morphology of the obtained weld structure [37].…”

Ultrasonic Inspection Techniques Possibilities for Centrifugal Cast Copper Alloy

“…When evaluation of the defects is based on the commonly used curves, the effects of differential attenuation in material lead to incorrect information about the defect size. Consequently, where the castings are tested, we identify only the presence of defects, its location and approximate size [2,5,8].…”

“…The second most fundamental problem is the change morphology and grain size of the castings microstructure. Large grain and morphology causes high attenuation of ultrasound in material, which should be countervailed choosing the right testing methods and accessories for testing [1,3,5].…”

Improvement of fatigue endurance of welded S355 J2 structural steel by severe shot peening

“…Weld contains several types of superficial defects and geometrical irregularities, especially cracks on the surface of weld or in the heat affected area, elevation of weld, undercuts in transitions to BM, defects in the root of weld and the internal defect such as pores, cold joints etc. [3][4][5][6]. It has been proven that shot peening (SP) and severe shot peening (SSP) are able to positively improve the fatigue endurance of several types of materials [7][8][9][10][11][12][13][14].…”