(合肥工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院， 合肥 230009)
摘 要: 采用直流四電極法研究了常壓下Sn-Zn合金系的電阻率隨溫度連續(xù)升溫的變化規(guī)律。結(jié)果表明： 合金Sn-Zn5、 Sn-Zn8.8、Sn-Zn20、 Sn-Zn30、 Sn-Zn40、 Sn-Zn50和Sn-Zn70分別在970、 1 008、 957、 950、 948、 926和873 ℃處發(fā)生了電阻率的突變現(xiàn)象。 對合金的進(jìn)一步分析表明， Sn-Zn熔體電阻率在高溫時(shí)的突變是由Zn在Sn-Zn熔體中大量汽化造成的， 即在此處發(fā)生了液-氣結(jié)構(gòu)轉(zhuǎn)變； Sn-Zn合金在完全熔化至發(fā)生液-氣結(jié)構(gòu)轉(zhuǎn)變的連續(xù)升溫過程中， 合金中并不存在某種液-液結(jié)構(gòu)的轉(zhuǎn)變， 且液-液結(jié)構(gòu)轉(zhuǎn)變并非存在于在所有二元合金系中。
關(guān)鍵字: Sn-Zn合金； 液態(tài)結(jié)構(gòu)； 電阻率； 汽化
temperature of Sn-Zn alloys
XU Wei, DING Hou-fu
（College of Materials Science and Engineering,
Hefei University of Technology, Hefei 230009, China）
Abstract: The change rule of electrical resistivity with the increase of temperatures of tin-zinc (Sn-Zn) alloys with different compositions were investigated using the direct current four-probe technique at constant pressure. The results show that some transitions occur at the temperatures of 970, 1 008, 957, 950, 948, 926 and 873 ℃. According to the analysis of the resistivity—temperature (ρ—t) curves, the obtained significant abnormal variation of the electrical resistivity at high temperature of Sn-Zn alloys is considered to be caused by the abundant gasification of Zn component in Sn-Zn alloys, namely the liquid-gas structure transition takes place in melts. And no temperature-induced liquid-liquid structure transition exists in Sn-Zn melts.
Key words: Sn-Zn alloys; liquid structure; electrical resistivity; vaporization
