纯钛铸件表面的酸洗

目的　探讨一种简便、有效的去除纯钛铸件表面污染层的方法。方法　室温下分别将 0 .2MPa、0 .4MPa和 0 .6MPa压力下喷砂 90sec的纯钛试件浸入HF :HNO3 为 1mol:5mol和 5mol:5mol的混合酸溶液中 10sec、30sec和 6 0sec ,观察反应情况 ,摄取酸洗后试件的金相组织照片 (× 40 0 )。结果　试件在HF浓度高时反应增强 ,反应速度加快。金相显微镜观察 0 .6MPa组试件经 2种混合酸溶液处理 6 0sec后 ,其表面污染层均已完全去除 ,其它处理组试件仍可见针状结晶层残留 ,但残留污染层厚度随HF浓度增加和酸洗时间的延长而减小。结论　经 0 .6MPa压力喷砂 90sec的试件在 1mol:5mol(HF :HNO3)混合酸溶液中浸泡 6 0sec即可将表面污染层完全去除

Acid treatment for dental pure titanium castings

Objective To investigate a convenient and effective method to remove contaminated layer from the surface of dnetal pure titanium castings.Methods The 8 pure titanium castings were sandblasted by 80 # white alumina at the pressure of 0.2 MPa(2), 0.4 MPa(2) or 0.6 MPa(4) for 90sec respectively.The 2 samples of each sandblasting groups were immerged respectively into acid combinations of 1mol:5mol (HF:HNO 3) and 5mol:5mol (HF:HNO 3) for 60sec.The 2 samples of 0.6 MPa group were immerged into 1mol:5mol (HF:HNO 3) for 10sec and 30sec,respectively.Reacting conditions and metallurgical phase of each samples were observed.Results The chemical reaction of titanium castings was stronger and faster in the acid combination with higher concentration of HF.The thickness of contaminated layer of titanium castings decreased with the increase of concentration of HF and the immerged time prolonging.The whole thickness of contaminated layer of samples sandblast at the pressure of 0.6 MPa was removed after immersion in the two acid combinations for 60sec.Conclusion The titanium castings could be immerged into 1mol:5mol (HF:HNO 3) acid combination for 60sec after 90sec sandblasting at the pressure of 0.6 MPa in order to get rid of the whole thickness of contaminated layer of its surface.