Tham khảo tài liệu 'handbook of extractive metallurgy 3 part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 1256 Handbook of Extractive Metallurgy Table Silver-based materials for electrical contacts. Compositions Electrical conductivity 1 Characteristic properties Uses Ag Cu Cd Ni CdO c SnO w Mo wc Alloys 104 tendency to weld low-current con- tacts wide use 705 88 higher mechanical strength relay contacts 90 10 88 and lower welding ten- 72 28 84 dency than fine silver 85 15 35 reduced welding tendency fuses early 77 31 type Composite metals 95 5 95 resistant to electrode bum- mechanically 90 10 87 ing formable and claddable and thermally 85 15 80 stressed domes- 70 30 55 tic equipment 60 40 44 40 60 25 90 10 92 resistant to electrode bum- heavy-current 50 50 62 ing large contacting forces switching 35 65 51 needed 50 50 52 similar to Ag-W some- heavy-current 40 60 47 what less resistant to elec- switching trode burning Composite materials 88 very resistant to welding fuses 95 5 84 intermediate coating 90 10 75 needed for soldering 85 15 65 102 extremely resistant to weld- low-voltage 99 1 99 ing brittle severe electrode heavy-current 98 2 77 burning switching slid- 95 5 55 ing contacts 90 10 35 95 5 slightly susceptible to open fuses aữ 92 8 welding break contac- 88 12 tors 65 35 57 resistant to electrode bum- heavy-current 50 50 47 ing very resistant to weld- fuses 40 60 37 ing difficult to work Copper 100. For example the composite system Ag-CdO can be produced by internal oxidation of the cadmium in an Ag-Cd alloy. In the case of molybdenum and tungsten silver can be absorbed into a matrix of these refractory metals. The important components in low-current technology are contact breakers relays sliding contacts plug and socket connectors soldered joints and screw connectors. The requirements for these contact materials are different from those for heavy-current technology. These include low contact resistance resistance to effects of the atmosphere and good abrasion resistance. A good connection must be obtained even after a .
