耐蚀钨基烧结合金及其制备方法

本发明公开一种耐蚀钨基烧结合金，由于改善了高温和高湿下的耐蚀性，这不需防护（如镀Ni）而使用。该耐蚀钨基烧结合金由80%～97%（质量）W和余量Ni、Co、Fe以及不可避免杂质组成，Ni-Co或Ni-Co-Fe粘结相的组成由Ni、Co和Fe比例为10%～98%（质量）Ni、2%～90%（质量）Co和0%～70%（质量）Fe所构成，通过在还原气氛下于比粘结相熔化温度高10-80℃温度液相烧结上述组成的混合粉而制得耐蚀钨基烧结合金体。（日本）

Microstructure and properties of ultra-fine tungsten heavy alloys prepared by mechanical alloying and electric current activated sintering

The microstructure and properties of the 93W-4Ni-2Co-1Fe(mass fraction,%) tungsten heavy alloys prepared by mechanical alloying and electric current activated sintering from mixed elemental powders were investigated.After 15 h milling,the average W grain size in the powders is decreased to 120 nm.For the powders milled for 15 h,the density,hardness and transverse rupture strength of the alloys sintered only by an intensive pulse electric current are the maximum.When the total sintering time keeps constant,the properties of the sintered alloys can be obviously improved by optimizing the sintering time of pulse-and constant-currents.A bulk ultrafine alloy with an average W grain size of about 340 nm can be obtained by sintering 15 h-milled powders in a total sintering time of 6 min.The corresponding sintered density,hardness and transverse rupture strength reach 16.78 g /cm3,HRA84.3 and 968 MPa,respectively.