On metal joining and the prediction of the strength of solid-phase joints

Modelling material transfer in metal rolling using plasticine

“…The results also suggest the importance of considering the differences in behaviour between different particle sizes, and the role of the gaps opening up between the oxide layers in determining the size of typical attachment particles. The influence of reduction, and hence gap contact area, on friction and bonding has been explained in terms of fracture of the oxide and micro-extrusion of material through the gaps [12][13][14][15][16]. The tests given in this paper show that, even without complications associated with fracture and micro-extrusion, the detailed mechanics of adhesion and metal transfer at these gaps between oxide plates is not trivial.…”

“…When lubrication fails, an oxide layer on the workpiece acts as a final barrier to prevent adhesion, so that the mechanical behaviour of the oxide layer plays an important role. Brittle oxide on the strip surface can be easily broken during the elongation occurring in metal forming, thus exposing fresh reactive metal [12][13][14][15][16]. Significant enhancement of adhesion between the tool and this fresh surface may be a critical factor in controlling transfer in metal rolling, implying that transfer layer formation in bulk forming processes is significantly different from that during many standard laboratory tests (e.g.…”

Progress in cold roll bonding of metals

“…Thus, the bond strength mentioned in this paper is determined by a tensile shear test, unless otherwise indicated. Kendall [45] addressed several methods for measuring interface properties using fracture mechanics by a cracking test, and much work has also been performed to calculate and predict the interface properties using the theory of material mechanics [46][47][48][49][50]. When applied, it will benefit greatly the development of new bonding processes and the improvement of bonding evaluation.…”

Improved ductile fracture criterion for cold forming of spheroidised steel

“…Continuum damage mechanics techniques have also been used to predict ductile fracture [17,18]. Kolmogorov and coworkers have introduced a phenomenological metal fracture model, which is used in practice of the metal forming in Russia [19][20][21][22][23][24][25][26][27][28][29][30]. Shabara et al [31] have assessed six widely recognised ductile fracture criteria utilising the experimental data from the cold upsetting of spheroidised steel specimens.…”

“…and f i is the value of the integral function, f(x), at the Gaussian point, ε i , which is obtained by finding the value of x at that point ξ = ξ i from Eq (27). and substituting in the integrand function f(x).…”