Features of the diamond films growth on the tungsten carbide surface by a copper underlayer

Surface preparation is a prerequisite for ensuring the required properties of a diamond film obtained by gas-phase deposition. The paper considers the effect of temperature and concentration of the etchant CuSO4 on the structural and phase composition of the surface of hard-alloy materials. The structural and phase composition of a continuous polycrystalline diamond film at its growth stages was also studied. Adhesion of the obtained diamond films to the surface of carbide materials was qualitatively determined. It has been established that surface treatment of a hard alloy in a CuSO4 solution at a temperature t = 23 °C leads to unequal removal of the cobalt bond with chipping of WC grains and the formation of a porous structure in the surface layer of the WC–6%Co alloy. The treatment with an etchant CuSO4 at t = –2 °С ensures uniform etching of the Co-bond along the WC grain boundaries and the formation of a chemically uniform surface. The orientational growth and adhesion of the diamond film depend on the elemental composition of the surface of the WC–Co alloy after treatment with a CuSO4 solution. If the treatment was carried out at a tsolution = 23 °C, then during the synthesis of the diamond film, the removal of copper from the defective surface layer of WC is difficult. This provides the multidirectional growth of diamond crystals in the film in two directions: <111> and <110>, which causes critical biaxial compressive stresses (2,5 GPa) and leads to low adhesion of the film to the surface of the hard alloy. If the treatment was carried out at tsolution = –2 °C, then the orientational growth of diamond crystals in the film occurs in one preferential crystallographic direction <111>. It reduces the biaxial compressive stresses (1,7 GPa) and increases the adhesive adhesion of the film to the surface of the hard alloy . The structure defect, calculated from the ratio of the lines of integrated intensities I1333 / I1580 using the Raman spectroscopy, decreases with concentration growth for negative temperatures and increases for positive ones of CuSO4 solution during surface preparation.

Ion Absorption Performance of Acrylic Copolymer Gel Fiber

In order to know the absorption performance of Acrylic gel fiber(AGF) on heavy metal ion and provide theoretical basis for its application research on sewage disposal area, Effect of CuSO4 solution temperature, concentration, PH, absorbing time and Na+ concentration on absorption properties were researched. The investigations showed that with increasing of solution temperature, absorption of Cu2+ increased first and then decreased. Absorbed amount of Cu2+ decreased gradually with the reduction of PH value in acidic solution. With CuSO4 solution concentration uprising, absorption capacity of AGF increased. With absorption time prolonged, absorption capacity increased rapidly first and then turned to ease gradually. Absorbed amount of Cu2+ reduced sharply to almost zero with the concentration of Na+ increased. The absorption behavior of Cu2+ and water molecule is highly correlated.