Adhesive bonding of steel for structural applications

Atmospheric pressure plasma effects on the adhesive bonding properties of stainless steel and epoxy composites

“…However, it accounts for 49% of the plasma-activated sample and 22% of the sanded and plasma-activated sample. The Cr 2 O 3 and Cr(OH) 3 species are present in all of the samples, however, Cr 2 O 3 is more prevalent than Cr(OH) 3 in the plasma-treated samples, whereas the reverse is true for those not exposed to the plasma. Figure 7.…”

“…Both of the samples that received plasma activation exhibited a higher degree of oxidation when compared to the control and sanded samples with the emergence of a peak corresponding to CrO 3 species. It is noted that the samples that received plasma activation exhibit a relatively low concentration of Cr(OH) 3 when compared to the control and sanded substrates. This is the opposite of what is seen in the iron spectra where hydroxyl groups are prevalent in the samples that were treated with the plasma.…”

Adhesiveness of cold rolled steels for car body parts

“…Both phenomena are caused by the penetration of humidity into the joints, associated with the severe atmospheric conditions simulated in the tests. According to the literature 1,7 , humidity can diffuse into the joints by capillarity, through microcracks formed in the adhesives or through microgaps present in the adhesive/adherent interfaces.…”

“…When structural adhesives are applied to join steel parts of the car body, the benefits are related to reducing the weight, increasing the rigidity, reducing vibration and noise and also closing gaps and holes. Also, particular attention is directed towards the finishing characteristics, since adhesive bonding of steel parts of car bodies reduces considerably the incidence of undesirable surface irregularities associated with welds, screws, nuts or rivets 6,7 . Besides that, it is well known that adhesive bonding is the preferred jointing method when fatigue of structures involving bonded parts is considered 8 .…”

“…Despite the advantages promoting the use of adhesive bonding of metallic parts, important issues remain to be solved, because the mechanical properties of bonded joints are generally influenced by a number of factors, such as the type of adhesive employed, the nature and surface roughness of the metallic adherents, the wet angle and the test temperature 1,2,[7][8][9][10][11] . Adhesive degradation due to exposure in atmospheres with high relative humidity and relatively high temperatures deserves special attention for the use of adhesive bonding in the automotive industry [8][9][10] .…”