The effect of the granulometric composition of the filler and heat treatment on the adhesion strength of multilayer metal coating on AlSiC MMC's surface

Background. Modern semiconductor power devices (SPD) contain temperature compensators (TC) in their design, which can be made of a metal matrix composite material based on an aluminum matrix alloy and silicon carbide micropowder (MMC AlSiC). A multilayer metal coating is applied to the TC surface, which makes it possible to firmly connect the TC with an active semiconductor crystal in the SPP. The adhesion strength of this coating to the surface of MMCM AlSiC largely determines the reliability of the SPP. The aim of this work is to study the effect of the granulometric composition of the filler and heat treatment on the adhesion strength of multilayer Al-Ti-Ni-Ag metal coatings on the surface of AlSiC MMKM.
Materials and methods. The studied samples of MMC AlSiC based on the AK9 aluminum matrix alloy were prepared by the method of vacuum-compression impregnation. As a filler, silicon carbide micropowders of grain size distribution F120, F150, F180 and mixtures F120 + M10P (10 %), F150 + M10P (10 %), F180 + M10P (10 %) were used. A four-layer metal coating (Al-Ti-Ni-Ag) was applied to the surface of the studied samples of MMCM AlSiC by magnetron sputtering. The adhesion strength of the bond between the coating and the composite surface was determined by the peeling method.
Results. The adhesive strength of a multilayer metal coating on the surface of MMC AlSiC samples with different grain-size composition of SiC filler was measured depending on the duration and temperature of annealing in an atmosphere of hydrogen and argon.
Conclusions. Annealing the samples under study in a hydrogen or argon atmosphere for more than 30 min at a temperature of 450$^{\circ}$C (or more than 60 min at a temperature of 350$^{\circ}$C) leads to a significant (almost threefold) increase in the adhesion strength of the metal coating.