Ion-beam assisted coating of tube inner walls by plasma immersion ion implantation

Tubes are often required to exhibit better performance in corrosion and wea r behaviour than the material the tube is made of can offer. The situation can be improved when the tube is coated with a protective film. This is pos sible when sputter coating with ions is performed. A sputter target is loca ted inside the tube. Energetic ions extracted from a plasma in which the tu be is immersed (plasma immersion ion implantation Pm) are accelerated towar ds the tube, enter it and impinge onto the target. Thus, material is sputte red from the target onto the inner wails of the tube. Tubes made of stainle ss steel and of tantalum were used. A part of the stainless steel tube was cut away and replaced by a segment of a silicon wafer. A zirconium sputter target was inserted into the tube. Ions from a nitrogen plasma were acceler ated into the tubs. Thus, zirconium oxynitride films were formed. Tantalum tubes with a platinum sputter target inside were treated in an argon plasma . The deposited films were analysed by Rutherford backscattering spectromet ry. The results show that PIII treatment of tube inner walls is an effectiv e technique for coating inner walls of tubes with protective films. (C) 200 0 Elsevier Science S.A. All rights reserved.