深冷处理对牙科铸造纯钛显微硬度及耐磨性的影响

Influence of cryogenic treatment on micro-hardness and abrasive resistance of dental casting pure titanium

目的探讨深冷处理对牙科纯钛铸件显微硬度及耐磨性的影响。方法制作40个牙科铸造纯钛试件,其中20个试件用于显微硬度测试,其余20个用于耐磨性测试,分别将其随机分为4组:对照组(A、A′组)、深冷处理组(B、B′组)、深冷处理和回火组(C、C′组)、循环深冷处理和回火组(D、D′组),每组5个试件。采用维氏硬度仪测定试件的显微硬度,喷砂磨损条件下重量损失量用于检测试件的耐磨性。结果 B、C、D组的显微硬度均高于A组,除B、D两组外(P>0.05),其余两两组间比较,差异有统计学意义(P<0.05),D组显微硬度最高。B′、C′、D′组重量损失量均低于A′组,两两组间比较,差异有统计学意义(P<0.05),D′组重量损失量最低。结论深冷处理是提高牙科铸造纯钛显微硬度及耐磨性的有效方法,其可能成为提高牙科材料性能的新方法。

Objective To discuss the influence of cryogenic treatment on micro-hardness and abrasive resistance of dental casting pure titanium.Methods 40 test specimen of dental casting pure titanium were prepared.Among them,20 ones were used for micro-hardness test,and the rest was used to test abrasive resistance.20 test specimens were ran- domly divided into 4 groups respectively： control group （group A and A＇）,eryogenic treatment group （group B and B＇）, cryogenic treatment and tempering group （group C and C＇）,and circulatory cryogenic treatment and tempering group （group D and D＇）,with 5 specimens in each group.The micro-hardness of specimens was tested by Vickers hardness tester and their abrasive resistance was determined by weight loss under the abrasive condition of sand blast.Results The micro-hardness of specimens in the group B,C,and D was harder than that in the group A.Except for group B and D （P〉0.05）,there was statistical difference between each two groups （P〈O.OS）.The micro-hardness of specimens in group D was the hardest.Weight loss in the group B＇,C＇,and D＇ was less than that in the group A＇,with statistical difference between each two groups （P〈0.05）.Weight loss in the group D＇ was the least.Conclusion Cryogenic treatment is an ef- fective way to enhance micro-hardness and abrasive resistance of dental casting pure titanium,which may become a new approach to improve dental material property.