Platinum-iridium alloys are widely used in modern industry and technology. Medium temperature thermocouple material, thick film resistors, precision instrument hairspring, standard resistance and Jordan farmar, dental materials and needle (1) meter material: they are a classic elv contact with conductive ring, highly reliable ignition engine materials, all kinds of precision instruments, sensors and micromotor with potentiometer winding and a silk materials, microelectronics technology in thick film resistance materials, etc. (2) Electrode materials in chlor-alkali electrolysis industry. (3) Dental materials and other medical materials. (4) Standard resistors, weights and meter sticks. (5)PtIr1O alloy and AuPd40 alloy can be paired as a medium temperature thermocouple, which is affected by iridium volatilization loss. In fact, platinum-iridium alloys with high iridium content are not suitable for long-term use at high temperatures. Alloys widely used in industry generally contain less than 30 percent iridium. PtIr5 and PtIr1O are classic potentiometer winding materials, PtIr17.5 is brush material, and PtIr25 is high reliable aero engine ignition contact material. Platinum-iridium alloy has been replaced by many gold base alloys as winding material and brush material, but PtIr25 alloy has never been a reliable replacement material.
1. The melting point of platinum crucible is 1773.5℃, and the operating temperature shall not exceed 1200℃, and the crucible shall not be directly heated over the open flame.
2. Do not use the crucible with too much force to avoid deformation or bump. Do not use the pointed end of the glass rod to take the contents of the crucible.
3. Oxides, hydroxides, barium oxide, sodium thiosulfate, phosphorus and substances containing large amounts of sulfur shall not be heated or fused in the platinum crucible; The nitrates, nitrites, oxides, and chlorides of alkali metals form brittle platinum and platinum phosphate at high temperatures, and all can erode platinum.
4. Samples and compounds containing heavy metals such as aluminum, bismuth, tin, arsenic, silver, copper, etc., shall not be burned and heated in platinum crucible.
5. Do not contact with any other metal (iron plate, electric stove, etc.) when heating at high temperature, be careful not to touch the corner.
6. Halogens such as aqua aqua (a mixture of concentrated hydrochloric acid and concentrated nitric acid), bromine water and hydrochloric acid and oxidants (chlorate, nitrate, permanganate, manganese dioxide, chromate, nitrite) shall not be treated in the platinum crucdron. Ferric chloride has a significant erosion effect on platinum, so it cannot contact with ferric chloride.
7. Do not heat or dissolve unknown substances in platinum crucible.
8. Platinum crucibles must be kept clean and bright inside and outside. After a long period of burning, the platinum crucibles may become dull outside.
9. Crucible treatment method: A. Boil it in dilute hydrochloric acid or dilute nitric acid (it is convenient to use diluted hydrochloric acid and mix it into (1.5-2) mol/L hydrochloric acid solution). Note that the acid used must not contain nitric acid, nitrate, halogen or other oxidants. If dilute acid is not enough to wash, wash c by melting potassium pyrosulfate, sodium carbonate or borax. If there is still a stain, or the surface of the black, then through the 100 sieve purpose without sharp edges and corners of fine sand, water wetting gently rub, make the surface restore luster.
