Corrosion()
A. only occurs beneath the surface of a metal or alloy
B. can lead to weakening of the metal or alloy
C. prevents liberation of elements from the metal or alloy
D. A and B
Ways to ensure that an alloy consists of small(rather than large)grains include()
A. combining it with citric acid
B. adding a grain refmer
C. cooling the molten metal slowly
D. copper,osmium,and iridium
缩合型硅橡胶印模材料的固化过程是()
A. 缩聚反应
B. 自由基聚合反应
C. 加聚反应
D. 以上都不是
α-氰基丙烯酸酯粘接剂的固化过程是()
A. 缩聚反应
B. 阳离子聚合
C. 自由基聚合
D. 阴离子聚合