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钛属于多晶形金属并以两种同素异形体存在:低温时为具有六方密排晶格的α-钛,高温时为具有体心立方晶格的β-钛。杜维斯的研究[1]业已确定,在非合金钛中甚至当冷却速度约每秒钟15000℃时,也不能阻止β-钛向α-钛的转变。但是,采用能溶于β-钛中的元素使钛合金化时,引起β-固溶体(β-相)在低温时转变温度和稳定性的下降。正如沃尔(?)尔指出的[2],元素对钛的同素异形体转变温度的影响决定于元素在门捷列夫周期表中的位置,而且原子价高于四价的过渡元素可降低转变温度,原子价愈高降低
Titanium is a polymorphic metal and exists as two allotropes: α-titanium with a hexagonal close-packed lattice at low temperatures and β-titanium with a body-centered cubic lattice at high temperatures. Davis’s study [1] has determined that in non-alloyed titanium, the conversion of [beta] -titanium to [alpha] -titanium is not prevented even when the cooling rate is about 15000 [deg.] Celsius per second. However, the alloying of titanium with elements soluble in β-titanium causes a decrease in the transition temperature and the stability of the β-solid solution (β-phase) at a low temperature. As Walter (1990) points out, [2] the effect of the element on the allotropic transition temperature of titanium depends on the position of the element in the Mendeleev’s periodic table, and the transitional element of higher valence than the tetravalent Reduce the transition temperature, higher atomic value lower