ABSTRACT:Objective To investigate the surface roughness of Co-Cr alloy fabricated by laser rapid forming(LRF)and formed by casting method after soaking in sterile artificial saliva with different concentrations of NaCl,and to compare the corrosion resistance of the two alloys.Meth-ods Twenty-four LRF alloy samples and 24 casting alloy samples were immersed in sterile artifi-cial saliva with different concentrations of NaCl(0.9%,2.0%,3.0%)after grinding and polis-hing.The surface roughness(Ra value)was measured after immersion for 8 weeks,and then the surface morphology was observed by field emission scanning electron microscope(FESEM).Re-sults The Ra values of both LRF alloy and casting alloy significantly increased after immersion in artificial saliva with 2%and 3% NaCl(P <0.05).Compared with casting alloy,Ra value of LRF alloy significantly increased after immersion in artificial saliva with 2% and 3% NaCl(P <0.05). No significant difference in Ra value was found between the two alloys after immersion in artifi-cial saliva with 0.9% NaCl(P >0.05).Compared with artificial saliva with 0.9% or 2.0% NaCl, Ra values of both LRF alloy and casting alloy significantly increased after immersion in artificial saliva with 3% NaCl(P < 0.05).In addition,the surface morphology observed by FESEM was consistent with the surface roughness of the two alloys.Conclusion The increased Ra values and decreased corrosion resistance are associated with the increased NaCl concentrations in Co-Cr al-loys.The corrosion resistance of LRF Co-Cr alloy was better than that of casting Co-Cr alloy at high chloride concentrations.%目的：将激光快速成形钴铬合金（LRF 钴铬合金）、铸造钴铬合金试件置于不同氯离子即不同 NaCl 的质量浓度的无菌人工唾液中浸泡，观察这2种钴铬合金在浸泡前后表面形貌的变化，并比较它们的抗腐蚀性能。方法制备 LRF 钴铬合金试件及同种成分和组成的铸造钴铬合金试件各24块，打磨、抛光后将其静态浸泡于 NaCl 质量浓度分别为0．9％、2．0％及3．0％的无菌人工唾液（分别简称为0．9％、2．0％及3．0％NaCl 唾液）中，8周后测量试件的表面粗糙度（Ra 值），并结合扫描电镜观察试件的表面形貌变化。结果2．0％及3．0％NaCl 唾液中的2种钴铬合金试件，其 Ra 值均较浸泡前增加（P ＜0．05）；0．9％NaCl 唾液中2种试件相比 Ra 值差异无统计学意义（P ＞0．05）。3．0％和2．0％NaCl 唾液中 LRF 钴铬合金的 Ra 值高于铸造钴铬合金（P ＜0．05）；3．0％NaCl 唾液中 LRF钴铬合金、铸造钴铬合金 Ra 值均高于0．9％、2．0％NaCl 唾液（P ＜0．05）。扫描电镜下观察到的合金试件表面腐蚀程度与试件的 Ra 值程度一致。结论随着 NaCl 浓度的增加，2种钴铬合金的 Ra 值也增大，其抗腐蚀性能下降。提示在高氯离子环境中，LRF 钴铬合金的抗腐蚀性能优于铸造钴铬合金。
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