Lapping pad will be worn during lapping process. Therefore, the quality of the work piece and the material removal ability will be lower. First, in this paper, it propose a intermittently nickel-electroplating lap-ping pad in lapping process : At first, plate a layer of nickel on copper plate and used it to be lapping pad. Replate the lapping pad to restore the working ability when the working ability of lapping pad decreased be-cause of wear. Secondary, it propose another restore method : composite electroplating on grinder in process. When grinding by using Ni-SiC composite coating pad, it is used to restore the pad by Ni-SiC composite electroplating at the same time. At first, the influence of load and rotation speed on mate-rial removal are investigated in this study. It is found that the material removal increased as the rotation speed of lapping pad and load increased. It is also found that the roughness of sin-tering SiC decreased as the load increased at a constant rotational speed. And at constant load , the influence of rotation speed on roughness of sintering SiC is unapparent. The ability decay of material removal of lap-ping pad is as time as go by. It can complete restore the wore lap-ping pad to unwear state by replating 15 minutes with 2.5 cur-rent density. The restored pad¡¦s behavior of material removal and roughness is the same as a new one¡¦s. The material removal of sintering SiC of composite electro-plating on grinder in process by using Ni-SiC composite coating is bigger than the material removal of sintering SiC of lapping by nickel-electroplating lapping pad. The material removal increase to 1.7 ~ 3.8 times in 90 minutes at the same load and rotation speed. And the material removal and time are linearly depend. It is investigated that the working ability of grinding disk can be maintain constant. It is also found that the material removal increased as the rotation speed of lapping pad and load in-creased.

In conventional abrasive machining , it must using dresser to dress the surface of polishing disc periodically , in order for polishing disc to maintain its ability of machining , and then ensuring the quality of work piece. It will make polishing disk thin , finally it must losing it ability of machining , and then be replaced by a new disc. For this reason , in the study , an idea of a new type ultraprecision polisher is proposed . Using Sn-Al2O3 composite coating to reach the mirror surface grinding of silicon wafer in the tin bath , and grinding with electroplating continuously . It will ensure the ability of machining of polishing disc . In the study , first , analyzing the effect of rotational speed rate of wafer and polishing disc on the grinding trajectories type of machining surface . From the result of analysis , find that , when the rotational speed rate is more irregular or it could not divided , the arrangement of grinding trajectories is more complex . And then , investigating the effect of cathode current density , rotational speed of polishing disc and time of plating on the characteristics of composite coating . In the experiment of composite electroplating , when cathode current density is higher , the size of crystal is smaller , the thickness of coating is thicker , and the quantity of Al2O3 within coating decrease lightly . The increase of the rotational speed of polishing disk could increase the size of crystal , the thickness of coating and the quantity of Al2O3 lightly . The time of plating is longer , the shape of crystal is more obvious , the thickness of coating is thicker and it also increase the quantity of Al2O3 . Finally , investigating the effect of cathode current density and cationic surfactant PEI on the characteristics of coating and wafer . In practical abrasive machining , the removal rate of wafer increases with cathode current density , and the addition of PEI could increase the quantity of Al2O3 indeed . Besides , under the same machining condition , in the tin bath with PEI , the removal rate is higher than the one in the tin bath without PEI .

In the study, the effect of current density and rotation speed of grinding disk on characters of Ni-Diamond composite coating are investigated. Experimental results show that current density and film thickness are almost linearly depend. When the current density is increased, the film thickness is increased, too. And it can cover diamond particles much more efficiently. The rotation speed of grinding disk is 20 rpm, the average deposition rate is approx. 2£gm/min in 5 ASD. When reduce the current density to 2.5ASD, the average deposition rate reduce to approx. 1.08£gm/min. The current density is 5 ASD, the covered area of diamond particle in Ni-Diamond composite coating is 60% when the rotation speed of grinding disk is 0rpm. Increasing the rotation speed up to 100 rpm, the covered area of diamond particle in Ni-Diamond composite coating is down to 24% because diamond particle can`t stay in the same position in a long period. Secondary, we use composite electroplating on grinder in process to grind CVD diamond films, the effect of current density and loads on grinding characters of CVD diamond films by using the composite electroplating on grinder in process are investigated. The load is 4.2 kg, the surface roughness Ra is about 0.2 £gm when composite coating grind CVD diamond with no electroplating. But the current density is up to 2.5 ASD, Ra can down to 0.12£gm. The load is increasing to 6.3 kg, the Ra of CVD diamond films is about 0.16£gm.