瞬时热曝露对BTi-62421S钛合金组织和性能影响研究

Research on the Microstructure and Properties Influence of Titanium Alloy BTi-62421S under Transient Thermal Expoure

BTi-62421S是一种先进的近α型耐温钛合金,以1.5mm轧制板材为例,开展了瞬时热曝露试验。运用金相显微镜和力学性能试验机对组织和性能进行了分析和测试。结果表明,合金由片状α组织和极少量β转变组织组成,随热曝露温度变化,合金呈现出明显不同的温色特征。在热曝露参数600℃/5h条件下,合金组织较稳定,氧化膜致密度下降,并有富氧α层产生,随着曝露温度的提高,β转变组织开始积聚粗化,次生α相增多,组织稳定性开始下降,氧向基体扩散加剧,富氧α层厚度呈倍数增加,组织变化对合金强度无明显影响,但富氧α层严重降低合金塑性。

BTi-62421S is an advanced thermal endurance titanium alloy with near a type.A transient thermal exposure was carried out test with 1.5mm rolled sheet.The metallurgical microscopy and mechanical testing machine were used to analyse Microstructure and Properties.The results show that the alloy consists of flaky α and minute quantity β transition microstructure.Alloys appears different temperature and color characteristics with the heat exposure.The alloy is more stable,oxide film density is decreased and the oxygen enriched α layer prouced during thermal exposure parameters under 600℃/5h conditions.With the increase of temperature,β transition organization began to accumulate coarsening,secondary α increases,organizational stability began to decline,the diffusion of oxygen into the matrix intensified and the oxygen-rich α layer thickness increased exponentially.Microstructure change had no significant effect on the tensile properties of the alloy,but the oxygen-rich α layer reduced the alloy plasticity serioudy.