Designation:B777−15StandardSpecificationforTungstenBase,High-DensityMetal1ThisstandardisissuedunderthefixeddesignationB777;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginaladoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscriptepsilon(´)indicatesaneditorialchangesincethelastrevisionorreapproval.1.Scope1.1Thisspecificationcoverstherequirementsforfourclassesofmachinable,high-densitytungstenbasemetalpro-ducedbyconsolidatingmetalpowdermixtures,thecomposi-tionofwhichismainlytungsten.Thismaterialspecificationmaybeusedforbarepartsorforpartsthatmaybecoatedwithothermaterialsforprotectionagainstcorrosionandabrasion.1.2Thisspecificationdescribesphysical,mechanical,andmicrostructuraltestingofamateriallotbasedontheuseoftestcoupons,notactualparts.Sinteredpropertiestypicallyvarybothwithpartsizeandsamplinglocationwithinagivenpart.Resultsobtainedfromcoupontestingmaythereforedifferfromthepropertiesofaspecificlocationinalargerpart.1.3IntendedUse—Partsmadefromthismaterialarein-tendedforusessuchasweightsorcounter-balancesinstaticordynamicbalancing,high-speedrotatinginertiamembers,ra-diationshielding,hypervelocityimpact,andvibration-dampingapplications.Inselectingtheappropriatealloyforagivenapplication,itisimportanttonotethatasthetungstencontentofthealloyisincreased,stiffness,radiationattenuation,anddensityincreasewithanaccompanyingdecreaseinattainableductility.1.4SpecialApplications—Forparticularapplications,prop-ertiesorrequirementsotherthanthosespecifiedinSections5,6,and7ofthisspecificationmaybeimportant.Thesealloysmaycontainelementswhichmakethemweaklyferromagnetic.Wherefreedomfrommagneticresponseisrequired,thisshouldbespecifiedinthepurchaseorder.Class4isnotavailableinanon-magneticgrade.Forpurposesofthisspecification,non-magneticmaterialisdefinedasmaterialhavingamaximummagneticpermeabilityof1.05(seeTestMethodA342).Alsoforspecialapplicationsinvolvinglargesections,methodsfordetermininginternalquali...
