新型鋯鈦合金的動(dòng)態(tài)拉伸力學(xué)性能與微觀(guān)斷裂機(jī)制試驗(yàn)研究
Tests ofdynamic tensile properties and microscopic fragment mechanism for a new zirconium-titanium alloy
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摘要: 采用直接撞擊式Hopkinson拉桿裝置對(duì)新型鋯鈦合金材料在動(dòng)態(tài)沖擊載荷作用下的力學(xué)性能進(jìn)行了試驗(yàn)研究，得到了典型動(dòng)態(tài)拉伸真應(yīng)力-真應(yīng)變曲線(xiàn),。試驗(yàn)結(jié)果表明,，在室溫、應(yīng)變率為800~4000s-1的情況下,，材料的動(dòng)態(tài)強(qiáng)度（包含屈服強(qiáng)度σ0.2,、抗拉強(qiáng)度σb）、失穩(wěn)應(yīng)變,、伸長(zhǎng)率以及應(yīng)變能密度均隨應(yīng)變率的增大而增大,。采用掃描電子顯微鏡（SEM）對(duì)試件斷口進(jìn)行分析，研究了合金材料在不同應(yīng)變率狀態(tài)下的失效斷裂特征,。結(jié)果發(fā)現(xiàn),，隨應(yīng)變率的增大，材料的斷裂方式由準(zhǔn)解理斷裂變?yōu)轫g性斷裂,。Abstract: Dynamic tension tests were conducted by employing the SHTB(split Hopkinson tension bar)to study the dynamic machanical properties of a new zffconium-titanium alloy. The dynamic mechanical properties of the alloy were determined at high strain rates ranging from 800 S-1 to 4000 S-1 at room temperature. The results show that the mechanical behavior of zffconium-titanium alloy depends on the strain rate, the dynamic strengths(including σ0.2 and σb), the unstable strain, the elongation, and the strain energy density all increase with the increase of the strain rates. The SEM fractographic observation shows that there exists a strain rate dependence of the fracture mode for the alloy sample. At room temperature and 800 S-, the sample is brittle, but its fracture modes changes from a quasi-cleavage one to a ductile one with increased strain rates.
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