摘要:
采用有限元法分析Ni-Cr合金与陶瓷连接冷却过程中界面残余应力形成的大小和分布特征.结果表明,Ni-Cr合金与陶瓷存在较大的线膨胀系数差,在界面间会产生较大的残余应力,并因为边缘效应在拐角处产生应力集中,残余应力最大值出现在Ni-Cr/陶瓷界面的近瓷侧,可达131 MPa.Ni-Cr/陶瓷界面残余应力σz较大值出现在Ni-Cr/陶瓷界面近瓷侧的狭小区域内,剪应力τzx的较大值出现在金/瓷界面,向合金和陶瓷两侧递减.采用钛中间层缓解了Ni-Cr/陶瓷界面残余应力,使残余应力向钛中间层转移,残余应力σz较大值出现在钛中间层,剪应力τzx最大值出现在Ni-Cr/Ti界面;随着钛中间层厚度增加,界面残余应力σz增大,剪应力τzx变化不大.
Abstract:
The numerical value and distribution of residual stress in the bonding interface of Ni-Cr/porcelain and Ni-Cr/Ti/porcelain have been investigated by finite element method.The experimental results show that there is much difference in thermal expansion coefficient between Ni-Cr alloy and proclaim.Larger residual stress will be produced at the interface.Due to produced stress concentration at the corner resulted in edge effect,the maximal value of residual stress is 131 MPa,which appears at the Ni-Cr alloy/proclaim interface near proclaim side.The greater σz value appears in a narrow area on the near porcelain side.The greater shearing stress τzx value appears in the Ni-Cr/porcelain interface,and gradually decreases to Ni-Cr alloy and porcelain sides.Residual stress and distribution position of Ni-Cr/Ti/porcelain has been improved when using Ti interlayer comparing with the residual stress of Ni-Cr/porcelain interface.Inner stress between Ni-Cr alloy and porcelain has been released and the residual stress is transferred to Ti interlayer;The thickness of Ti interlayer has effects on residual stress,the σz of interface is increasing and shearing stress τzx is little different with the interlayer thickness increasing.
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