Application and Upgrading of On-line Monitoring System for Measurement and Processing of Electric Signals at Arc Stud Welding Process
As the application of on-line monitoring system is shown to be a good solution during monitoring of main welding parameters at different welding processes, this paper describes application and upgrade of on-line monitoring system developed at Mechanical Engineering Faculty in Slavonski Brod. Experimental part of the paper shows application of on-line monitoring system during welding of two types of studs with application of activating flux for ATIG process (VS-2E) on the base metal surface. Monitoring of main welding parameters (welding current and voltage) was conducted during welding of studs usually used in steam boiler production (stud diameter: 10 mm), and welding voltage was monitored on the studs (shear stud) of 22 mm diameters used in bridge construction. The goal of monitoring and analyse of main welding parameters is to evaluate the connection of electric arc parameters variations with the presence of activating flux.
Reliability of Welding Parameters Monitoring System
This paper presents application of self developed On-line monitoring system for main welding parameters acquisition and data processing at arc welding and resistant welding process. Recorded data by On-line monitoring system is compared with data measured by oscilloscope. Based on comparation of both methods, it is possible to conclude that there are no significant differences between recorded data. Presented On-line monitoring system is appropriate and accurate enough for welding parameters monitoring and control.
Formation and Strength of Magnesia Whiskers
The formation of single-crystal magnesia whiskers during the compressive deformation of single crystals at room temperatures is described. These whiskers can have strengths of the order of millions of pounds per square inch. They are formed during fracture as a result of the discontinuous propagation of cracks which are mechanically relieving internal stresses resulting from plastic flow