At present, enhancement of hybrid metal joints for tensile pull-out load through overlap surfaces with a macro-scale roughness is one scope of research. The macro-scale roughness is established through the modified arc-welding process, called “cold metal transfer pin” (CMT-pin), which enables repetitive manufacturing of arrays of metal reinforcements (pins) on parent metal surfaces.Hybrid metal joints between parent steel sleeves and cast aluminium alloy have been investigated. Joint surfaces of parent steel sleeves, which have cylindrical cross-sections, are modified by cylinder and ballhead pins. Cast metal joints were tested under uniaxial tensile loading. At the same time, their load transfer behaviour was determined. Results of tensile tests of hybrid metal joints with different kinds of pins, as well as with different amounts of pins are presented. Comparisons with reference joints without pins or with steel sleeves containing a harmonious triangular polygon cross-section ("P3G") and endings with an enlarged diameter are carried out.The results show an enhanced load transfer performance in the case of hybrid metal joints with pins, as well as enhanced performance measures compared to reference joints. It is also shown that the pin quantity has a major impact on the ultimate joint strength and the irreversible energy absorption density. The use of a certain quantity of pins leads to a change of the failure shape of the joints, which includes steel sleeve pull-out and pin shear to rupture of the cast aluminium.
Aluminium AA7075 is well known as extrusions, plate or sheet metal predominately in aerospace applications. The continuing efforts for reducing the weight but still maintaining the safety of vehicle structures are opening up the way for this alloy in automotive applications. Since this branch is very different to space as well as aircraft industries in manufacturing methods, costs and production numbers, the development of appropriate processes is necessary. After showing a high potential for deep drawing of AA7075 sheets under elevated temperatures, the joining technology options are now under investigation too. Since spot welding is very common in automotive body-in-white manufacturing, an innovative version of this process is evaluated for applicability for welding AA7075-T6 sheets to each other and to proven automotive aluminium alloys. The results of sample weldments, including mechanical static strength, micrographs, hardness, radiography and parameters for a stable process range, are presented.
Modern visualization methods facilitate the user a better and deeper understanding of the welding process. Current methods and visualization systems are based on empirical groundwork. A simulation software on the basis of physical models is put at the disposal of the user, which facilitates a visualization of the weld joint geometry and temperature distribution. In this way corrupt weld joints can be detected and handled in advance. This leads to an increase of quality and profitability. For this reason, this approach offers a new benchmark in the world of electric arc technology and sets a basis for a variety of future visions. Physical welding models are so far optimized and reduced in order to facilitate a real-time simulation. The reduction of the models was achieved by a combination of analytical solutions with optimized numerical algorithms for partial differential equations. These measures facilitate the execution of a welding simulation in a very short time. Experimental support (provided by AUDI and Fronius) upon the calibration leads to well validated and reliable results. With modern visualization methods the results are user-friendly presentable. A demonstrator in the form of an expansion of the Fronius Virtual Welding system was set up. The demonstrator contains an offline and an online mode. The offline mode performs the analysis after the welding. The online mode performs the realtime (simulation) analysis during welding. The development is based on results from preceding developments such as Virtual Welding System (Fronius, FH JOANNEUM) and SimWeld Software (RWTH Aachen).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.