The aluminum/steel structural transition joints (STJs) are widely used in shipbuilding industry due to the advantages of joining these two materials with important weight savings while exploiting their best properties. The research objective is the evaluation of mechanical strength of explosion welded structural transition joints by imposing severe thermal loads in specific temperature ranges. Design/methodology/approach: Mechanical characterization of heat treated specimen have been performed to evaluate the influence of these thermal cycles on final joint resistance and evaluate the product in service. Several specimen aluminum/steel joints have been heated at specific temperature and time and air-cooled in compliance with a Central Composite Design (CCD) experimental plan to investigate the influenced of these factors on inter-metallic layers. Findings: The micro-hardness measurements have been pointed-out that the hardness of the inter-metallic compounds decreased with the temperature (values greater than 300°C). The processing time influence has been less significant in the observed temporal ranges. This trend has been also confirmed by evaluating the maximum strength of the bond Fe/Al interface. None of the specimens exhibited significant strength variation for thermal loads with temperature lower than 300°C, independently from the processing time. Research limitations/implications: This methodology is very useful to perform acceptance controls of STJ before use. Practical implications: These observations are very important to suggest the application of laser techniques to weld this type of joints, thanks to the very narrow localized thermal input. Originality/value: The paper presents an alternative and cheap way to assess quality of STJs from the mechanical point of view.
|Titolo:||Mechanical strength of Fe/Al structural transition joints subject to thermal loading|
|Data di pubblicazione:||2009|
|Appare nelle tipologie:||1.1 Articolo in rivista|