Post-transition metal packing structure. Tin forms Zintl phases such as NaSn, BaSn, KSn and CaSn. It has good corrosion resistance in air on account of forming a thin protective oxide layer. Pure tin has no structural uses. It is used in lead-free solders, and as a hardening agent in alloys of other metals, such as copper, lead, titanium and zinc. Lead is a soft metal (MH 1.5, but hardens close to melting) which, in many cases, is unable to support its own weight. It has a close-packed structure (BCN 12) but an abnormally large inter-atomic distance that has been attributed to partial
Dry lubricant room temperature to form a solid lubricant. Pastes are grease-like lubricants containing a high percentage of solid lubricants used for assembly and lubrication of highly loaded, slow-moving parts. Black pastes generally contain MoS. For high temperatures above 500 °C, pastes are composed on the basis of metal powders to protect metal parts from oxidation necessary to facilitate disassembly of threaded connections and other assemblies. Dry-powder tumbling is an effective application method. The bonding can be improved by prior phosphating of the substrate. Use of free powders has its limitations, since adhesion of the solid particles to the substrate is usually