Role of MoS₂ Addition in the Consolidation of Metal from Powder to Plate by the Compression Shearing Method at Room Temperature

Abstract

We use a Cu/MoS 2 composite to provide a new approach to control the consolidation of materials by compression-shearing at room temperature. Cu/MoS 2 samples were formed under several shearing distances and the resulting microstructures were observed and compared with pure Cu samples. The microstructural change related to the decrease in applied shearing force is discussed. The structural observations indicate that the reason for the decrease in shearing force appears to be the slip of the sample on the lower plate because of MoS 2 lubrication. The internal structure of the Cu/MoS 2 samples appears to be interrupted midway through the consolidation process by dissipating the applied shearing force. In contrast, particle bonding and grain refinement occurred only on the sample surface, as for the friction process, and extended gradually to the inside of the sample when the shearing distance increased. We controlled the metal consolidation by compression shearing at room temperature by dispersing MoS 2 into a Cu matrix. The shearing force appears to be more effective in metal consolidation by compression shearing at room temperature than the shearing distance.

Interparticle Bonding of Cu Powder under Repetitive Unidirectional Friction

“…Copper powder (99.9% purity, Fukuda Metal Foil & Powder Co., Ltd., Kyoto, Japan) was used as a feedstock because of its better tribological properties than those of Al or Ti, which were used in previous studies [6-8, 14, 20]. The powder was the same as that used in a previous study [16,17], and its average particle size and average crystal grain size were 38 and 5.0 μm, respectively. This powder was compressed under a uniaxial normal stress of 1000 MPa to obtain compressed samples with a target size of 20 × 20 × 0.25 mm 3 .…”

“…The conditions of the friction experiments were set to correspond with the forming conditions of the pure Cu plate formed by COSME-RT apparatus (DRD-NNK-002, DIP Co., Ltd., Gunma, Japan) [16,17]. To avoid oxidation of the sliding surface, all the tests were performed with 5.0 l/min nitrogen blowing around the contact.…”

“…Several methods for forming metals such as powder metallurgy and casting have been attempted to develop alternative metals and alloys [2][3][4][5]. Our research group has focused on a novel powder molding method, based on a compression shearing method at room temperature (COSME-RT) [6][7][8][9][10][11][12][13][14][15][16][17].…”