Minor problems arising from optimizations by welding of fixed prostheses frameworks can be identified by macroscopic and microscopic visual inspection. The purpose of this study was to highlight the visible discontinuities present in the laser welds of dental Ni-Cr alloys. Ni-Cr base metal alloys designated for fixed prostheses manufacture were selected for the experiments. Using cast plates, p...

Process monitoring is important for the laser welding system, especially for the weld seam deviation monitoring. A 10kW high power fiber laser butt joint welding of type 304 stainless steel was performed. By combing two different band pass filters, high speed photography was employed to capture the near-infrared images of molten pools. Image difference algorithm was used to obtain the weld seam...

introduction: the purpose of this study was to investigate the effect of 6w power carbon dioxide laser (co2) on the biologic compatibility of the sandblasting with large grit and acid etching (sla) titanium discs through studying of the sarcoma osteogenic (saos-2) human osteoblast-like cells viability. methods: sterilized titanium discs were used together with saos-2 human osteoblast-like cells...

This study evaluated the tensile and flexural strength of tungsten inert gas (TIG) welds in specimens made of commercially pure titanium (CP Ti) compared with laser welds. Sixty cylindrical specimens (2 mm diameter x 55 mm thick) were randomly assigned to 3 groups for each test (n=10): no welding (control), TIG welding (10 V, 36 A, 8 s) and Nd:YAG laser welding (380 V, 8 ms). The specimens were...

The punchless welding point detection system using laser diagnostics for continuous strip production line has been developed. At the entrance of the steel strip production line, the preceding and following coils are welded for continuous processing. The welding point detection and tracking of the position is essential for the setup change of various important processing facilities according to ...

Laser welding has been applied to various industries, in particular, automotive, aerospace and microelectronics. However, traditional off-line testing of the welds is costly and inefficient. Therefore, on-line inspection systems with low cost have being developed to increase productivity and maintain high welding quality. This paper presents the applications of acoustic, optical, visual, therma...

In this paper, a three-dimensional finite element model has been developed to simulate the laser-TIG hybrid welding (HLAW) of stainless steel 1.4418 with thickness of 4 mm. Transient temperature profile and dimensions of the fusion zone and heat affected zone (HAZ) during welding process are calculatedusing finite element method (FEM) and were solved in the ABAQUS/Standard software.The heat sou...

introduction: acne scar is formed after severe episodes of acne in teen and earlyadult years. several treatment options have been used for depressed acne scars suchas punch grafting, punch excision carbon dioxide (co2) laser etc. moreover, studiesshow that laser skin resurfacing such as co2 fractional can effectively treat depressedacne scars. we investigated the efficacy of fractional co2 lase...