JPS51138103U - Cantilever - Google Patents

Abstract

Light and rollable metal such as aluminium, titanium etc. is used as substrate for cantilever coated with material having high E/p rate such as beryllium, boron etc. by vacuum evaporation. For increasing adhesion of base and coated layer, materials should be heated more than 150°C. In case of aluminum as base, it tends to crack due to stress arising from the large difference of heat expansion ratio between materials. Therefore aluminium should be oxidized on its surface before coated with high E/p rate material. Table 1: Al: Young modulus E = 7,400, Density p = 2.65, E/p = 2,750, Heat-Expansion ratio (1/C) = 24.6x10^(-6) Al-Oxide: Young modulus E 35,000, Density p = 3.85, E/p = 9,090, Heat-Expansion ratio = 6.7 x10^(-6) Be: Young modulus E = 28,000, Density p = 1.84, E/p = 15.217, Heat-Expansion ratio =12.3 x10^(-6) Boron: Young modulus E = 45,000, Density p = 2.46. E/p = 18.292, Heat-Expansion ratio = 8.3 x10^(-6) Fig.1: 1 base substrate (aluminium pipe drawn for making tapered end) 2 oxidised aluminium, 3 coated layer of beryllium, boron, silica etc.