A very common helical surface in various mechanisms is a straight closed helicoid or screw conoid, known the technical field as screw. Considering wide application of screws, there are methods their production (winding, rolling, stamping, stretching flat rings welded together on shaft). Since conoid nondevelopable, ring an approximate sweep screw, since exact does not exist. During formation tu...

Thorsten W. Becker,1 Göran Ekström,2 Lapo Boschi3 and John H. Woodhouse4 1Department of Earth Sciences, University of Southern California, 3651 Trousdale Parkway, Los Angeles CA 90089-0740, USA. E-mail: [email protected] 2Department of Earth and Environmental Sciences, Lamont-Doherty Earth Observatory, Palisades, NY 10964, USA 3Eidgenössische Technische Hochschule, Zürich, Switzerland 4Department of ...

In the present study, parameters of tool rotation speed, tool travel speed and tool offsetting with different levels were used in the friction stir welding (FSW) of aluminum-copper tailor welded blanks (TWBs). The FSW of pure copper to 5052 aluminum alloy were carried out by varying tool rotation speed from 800 rpm to 1200 rpm, tool travel speed from 40 mm/min to 80 mm/min and tool offsetting f...

The aim of this study is to evaluate the microstructures, tensile lap shear strength, and fatigue resistance of 6022-T43 aluminum alloy joints welded via a solid-state welding technique-ultrasonic spot welding (USW)-at different energy levels. An ultra-fine necklace-like equiaxed grain structure is observed along the weld line due to the occurrence of dynamic crystallization, with smaller grain...

To improve the usage of material in fatigue loaded complex welded structures a better calculation method (based on FEA) is needed than what is available on the market and an improved management of weld quality. Improved FE-procedures are directly applicable to design of generic structural components within virtually all industries using CAD and FEtools, irrespective of industrial sector. More a...

Metallic tracheal stents have been used in the treatment of paediatric tracheomalacia for more than a decade. We describe a case in which critical airway obstruction occurred during removal of a welded tracheal stent using a rigid bronchoscope under general anaesthesia. Life-saving cardiopulmonary bypass was instituted urgently, and the welded stent was then removed successfully by directly ope...

OBJECTIVE To compare the deflection load characteristics of homogeneous and heterogeneous joints made by laser welding using various types of orthodontic wires. MATERIALS AND METHODS Four kinds of straight orthodontic rectangular wires (0.017 inch × 0.025 inch) were used: stainless-steel (SS), cobalt-chromium-nickel (Co-Cr-Ni), beta-titanium alloy (β-Ti), and nickel-titanium (Ni-Ti). Homogene...

It is shown that the responsible parts of each vehicle are tubular connecting lines, which included into braking, fuel and exhaust systems cars. These pipelines have high requirements for reliability, vibration resistance, strength, corrosion resistance durability. used as expanders elements when transitioning from a smaller pipeline diameter to larger one. The paper presents studies operation ...

The objective of this study was to investigate the effects of cryo-treatment on the microstructure, corrosion behavior, and mechanical properties of Ti before and after laser welding. The microstructure was studied by optical microscopy. It was found that the grain size for Ti became smaller after cryo-treatment. Cryo-treatment could also refine and stabilize the crystal lattice structure and d...