Application of Metal Sputtering Treatment to Cellulose Materials Used as Co-Deposited Material for Electrolytic Nickel Composite Plating

Abstract

Since ancient days, pulpwood, which is a fibrillated plant fiber, has been used as a raw material for paper products 1,2) . In recent years, there has been a growing trend toward the industrial use of cellulose fiber which is obtained from renewable resources, plants due to the new sustainable development policies 3,4) . The annual production of plants derived cellulose on the Earth is estimated to be 7.5×10 10 -1.5×10 12 tons [5][6][7][8] , making it a highly sustainable resource. Especially, the cellulose fiber that has been fibrillated to the nanoscale is called cellulose nanofiber (CNF), which has been attracting attention for its excellent properties [9][10][11] . Although its density (1.5-1.6 g/cm 3 ) 12) is 1/5 times lower than that of steel, the strength of a single nanofiber in the longitudinal direction reaches 1.6-3 GPa 13) . This value is approximately five times in maximum the tensile strength of JIS S50C (610-740 MPa), which is a commonly used for structural steel. CNF is able to be used as reinforcement in composite materials with polymers to enhance their mechanical, thermal, and biodegradation properties 14) . CNF composited polymers have shown better mechanical performance compared to the base polymer, making them suitable for various industries 15) such as automotive 16) , packaging 17) , medical implant 18) , electronics [19][20][21] , building material 22) , and paper 23) . On the other hand, there are very few reports on composite materials with cellulose added to metal-based matrices, with only a few examples being the addition of CNF to sintered metal materials by Kurita et al. 24) and Osada et al. 25) Therefore, we have proposed and studied the fabrication of metal-based CNF composite films by a electrolytic composite plating method 26,27) . Further improvement of wear resistance due to the intervention of CNF is expected by compositing CNF into nickel (Ni) plated film which is widely used industrially for its superior corrosion, wear, and heat resistance. In addition, when Ni-CNF plating is applied to the surface treatment of electronic substrate electrodes, the presence of CNF, which is chemically stable and has a low linear thermal expansion coefficient, is expected to suppress the formation of intermetallic compound (IMC) between solder/electrode and relieve thermal stress.

An Evaluation of the Wear Resistance of Electroplated Nickel Coatings Composited with 2,2,6,6-Tetramethylpiperidine 1-oxyl-Oxidized Cellulose Nanofibers

“…Figure 6 shows the appearance of the plated films. As in previous studies [ 2 , 3 , 4 ], the plated film without CNF was matte, and the plated film with CNF was bright, while the plated film with CNF showed uneven brightness under the conditions where 2 and 3 g/L of CNF were added.…”

“…In this study, Ni–cellulose nanofiber composite electroplated films were fabricated on steel plates using a nickel electroplating solution with the addition of cellulose nanofibers. The plating process was mainly based on previous studies [ 2 , 3 , 4 ], and the range of 1–3 g/L for the addition of cellulose nanofiber was also determined based on our previous study [ 4 ]. The obtained plated films were evaluated in terms of surface morphology, quantitative analysis, surface hardness, and Ni crystallite size.…”

“…We have been developing a new functional coating, a nickel (Ni)–cellulose nanofiber composite electroplated film, with sustainable properties [ 1 , 2 , 3 , 4 ]. Dispersion enhancement and self-lubricating properties are expected to be achieved by compounding cellulose nanofibers, which are renewable resources obtained from plants, are five times stronger than steel at one-fifth of the density, and are crystalline resin [ 5 ].…”

“…Cellulose nanofibers can be used as a composite material, and, in particular, cellulose nanofiber composite resins have attracted a great deal of attention [ 6 , 7 ]. Cellulose nanofiber composite resins have shown better mechanical performance than the base polymer, making them suitable for various industries [ 3 , 8 ], such as the automotive [ 9 ], packaging [ 10 ], medical implant [ 11 ], electronics [ 12 , 13 , 14 , 15 ], building material [ 16 ], and paper industries [ 17 ]. However, very few studies have reported on composite materials with cellulose added to metal-based matrices.…”

“…As described above, Ni–cellulose nanofiber composite electroplated films have many advantages in terms of sustainability and a low environmental load. In our previous studies [ 1 , 2 , 3 , 4 ], their fabrication conditions were investigated and revealed; however, their wear resistance has not yet been evaluated. Therefore, in order to evaluate the wear resistance and clarify the abrasion mechanism, the properties of Ni–cellulose nanofiber composite films plated on steels were investigated, and ball-on-disk abrasion tests under non-lubricated (dry) conditions and an analysis of the macro- and micro-structures of abrasion scars were conducted.…”