Alloy composition and metal/mold heat transfer efficiency affecting inverse segregation and porosity of as-cast Al–Cu alloys

A Comparative Study of Additively Manufactured Thin Wall and Block Structure with Al-6.3%Cu Alloy Using Cold Metal Transfer Process

“…The hydrogen pores are mainly formed through heterogeneous nucleation, and grow in the form of self-diffusion or combination in the solidification of the aluminum alloy. The nucleation rate of hydrogen pores is closely related to the grain size with certain hydrogen content [14,[17][18][19]. Meanwhile, the temperature gradient, cooling rate and heat input are the key factors affecting the grain size.…”

Numerical and experimental investigation of microporosity formation in a ternary Al–Cu–Si alloy

“…The numerical model approach used to simulate the macrosegregation profile during solidification is based on a model previously proposed by Voller [15,16] and modified by Boeira et al [21,22] to deal with microporosity formation. For times t < 0, the molten alloy is at the nominal concentration C 0 , and contained in the insulated two-dimensional mold defined by 0 < x < X b and 0 < y < Y b .…”

“…where K 0 is equal to 2.822 × 10 −7 [23] and the solubility of hydrogen can be obtained through the application of Van't Hoff equation [24], whose parameters A and B are functions of the local mass concentration of solute and are those used by Boeira et al [21,22]. Once the barrier imposed by the nucleation condition, given by Eq.…”

Copper passivation by metal doping

“…Alloys in their various compositions are used in specialized applications of metallurgy [2], microelectronics [3], heterogeneous catalysis and hydrogen storage media [4,5]. Copper-based alloys are widely used in many environments and applications because of their excellent corrosion resistance coupled with combinations of other desirable properties such as superior electrical and thermal conductivity, ease of fabricating and joining, and resistance to bio-fouling [6]. The composition of Cu-base alloys can be subtly varied to increase the mechanical strength, enhance formability and resistance to atmospheric corrosion.…”

“…Instead Cr, Ti, Al and Mg have been observed to passivize copper surfaces [2,3]. Al-containing copper alloys have high corrosion resistance, and they have been widely used in several fields ranging from microelectronics to aerospace [29][30][31]6]. The results of refractory metal nitration of Cu thin films deposited on Si 2 O show that a protective layer can be formed by annealing either a Cu-(27 at.% Ti) or a Cu-(26 at.% Cr) alloys.…”