一合金之成分为90Pb-10Sn。(a)请问此合金在100℃、200℃、300℃时含有哪几种相?(b)在哪个温度范围内将只有一相存在?(参看图4-9)Composition of an alloy is 90Pb-10Sn. (a) Which phases is contained at 100℃, 200℃, 300℃? (b) In which temperature range will be only one phase exists? (See Figure 4-9).327-|||-300 c-|||-d L-|||-250-|||-α-|||-α+L-|||-() 200 b β+L-|||-R 18 β-|||-150 e-|||-100 a alpha +beta -|||-50-|||-1 1 1-|||-o 10 20 30 40 50 60 70 80 90 100%-|||-100 Sn-|||-P答:(a)成分为90Pb-10Sn的合金对应的为红色的垂直线,分别在100℃、200℃、300℃作水平线得到交点a,b,c,所以100℃时,交点a位于α+β相区,所以有α和β两相。200℃时,交点b位于α单相区,所有只有α一相。300℃时,交点c位于液相线上,此为两相共存线,所以有液相L和α两相。( )A. Composition of alloy is 90Pb-10Sn alloy which corresponding to the red vertical line, it intersect with the temperature level line at a, B. and C. points. So, there are two phases at 100℃, α and β; there is only one phase at 200℃, α; point c lies on the liquidus line, so there are two phases at 300℃, L and α. D. f, then draw horizontal lines to get the corresponding temperature. So when the temperature is more than 300℃, liquid phase L exists. When the temperature is between 148 ~ 268℃, there is only α p E. and F. G. et three points, d, e and f, then draw horizontal lines to get the corresponding temperature. So when the temperature is more than 300℃, liquid phase L exists. When the temperature is between 148 ~ 268℃, there is only α phase.