Abstract: The lapping experiment of single crystal sapphire dome using micro-diamond magnetic abrasive under the control of magnetic field was studied .The effects of lapping pressure , lapping time and ethylenediamine concentration on the removal rate and surface roughness of single crystal sapphire dome were studied systematically .The experimental results show that with the increase of lapping pressure , the removal rate increases but the increase is reduced and the surface roughness decreases but the decrease is reduced.When the concentration of ethylenediamine was 3;and pressure was 25 kPa, the removal rate in the first 30 min can remain above 5 μm· h -1 , but after 30 min, the removal rate began to appear a significant decline .Surface roughness in the first 30 min was reduced to about 110 nm quickly , slightly lower after 30 min.

Key words: The lapping experiment of single crystal sapphire dome using micro-diamond magnetic abrasive under the control of magnetic field was studied .The effects of lapping pressure , lapping time and ethylenediamine concentration on the removal rate and surface roughness of single crystal sapphire dome were studied systematically .The experimental results show that with the increase of lapping pressure , the removal rate increases but the increase is reduced and the surface roughness decreases but the decrease is reduced.When the concentration of ethylenediamine was 3;and pressure was 25 kPa, the removal rate in the first 30 min can remain above 5 μm· h -1 , but after 30 min, the removal rate began to appear a significant decline .Surface roughness in the first 30 min was reduced to about 110 nm quickly , slightly lower after 30 min.