Alloys
Chemistry · मिश्र धातुएं
📋Quick Overview
An alloy is a homogeneous mixture of two or more metals, or a metal with a non-metal. Alloys are made to improve properties like hardness, strength, and resistance to corrosion. This is one of the MOST ASKED topics in competitive exams — you must memorize the composition of at least 20 alloys.
📖Alloys — Master Table
| Alloy | Composition | Uses |
|---|---|---|
| Brass | Cu + Zn (Copper + Zinc) | Utensils, musical instruments, decorative items |
| Bronze | Cu + Sn (Copper + Tin) | Statues, medals, coins, bells |
| Steel | Fe + C (Iron + Carbon 0.1-2%) | Construction, tools, machinery |
| Stainless Steel | Fe + Cr + Ni + C (Iron + Chromium + Nickel + Carbon) | Kitchenware, surgical instruments, cutlery |
| Solder | Pb + Sn (Lead + Tin) | Joining/welding electrical wires, plumbing |
| German Silver | Cu + Zn + Ni (Copper + Zinc + Nickel) | Utensils, coins, decorative items (NO silver!) |
| Gun Metal | Cu + Sn + Zn (Copper + Tin + Zinc) | Guns, gears, bearings |
| Bell Metal | Cu + Sn (Copper 80% + Tin 20%) | Bells, gongs |
| Duralumin | Al + Cu + Mg + Mn | Aircraft bodies (light + strong) |
| Magnalium | Al + Mg (Aluminium + Magnesium) | Balance beams, light instruments |
| Nichrome | Ni + Cr + Fe (Nickel + Chromium + Iron) | Heating elements (electric heaters, toasters) |
| Constantan | Cu + Ni (Copper 60% + Nickel 40%) | Thermocouples, resistance wire |
| Amalgam | Any metal + Mercury (Hg) | Dental fillings |
| Sterling Silver | Ag + Cu (Silver 92.5% + Copper 7.5%) | Jewellery, coins, silverware |
| Type Metal | Pb + Sn + Sb (Lead + Tin + Antimony) | Printing press type |
| Pewter | Sn + Pb + Cu (Tin + Lead + Copper) | Decorative items, tableware |
| Invar | Fe + Ni (Iron 64% + Nickel 36%) | Clock pendulums, measuring tapes (low expansion) |
| Monel | Ni + Cu + Fe (Nickel + Copper + Iron) | Chemical equipment, marine hardware |
| Alnico | Al + Ni + Co (Aluminium + Nickel + Cobalt) | Permanent magnets |
| Rose Metal / Wood's Metal | Bi + Pb + Sn + Cd | Fuse wire, fire sprinklers (low MP ~70°C) |