Preparation and Properties of Cu Matrix Reinforced with Ti₂AlN Ceramic Particles

Abstract

Cu matrix composites with various contents of Ti2AlN were fabricated by powder metallurgy using spark plasma sintering (SPS) method. Ti2AlN ceramic particles were pre-treated by electroless copper plating, the result showed that Ti2AlN reinforcement and Cu matrix were strongly bonded. The effects of Ti2AlN content on microstructure, electrical resistivity and mechanical properties were systematically investigated. With the addition of low fraction of Ti2AlN, the hardness and tensile strength of matrix were improved without losing the fracture toughness too much. Tensile strength of Ti2AlN/Cu composites were about 380 MPa with the content of 7 wt. % reinforcing phase, and the conductivity of the composites remained about 61.5 % IACS. Moreover, the wear tests illustrated that the loads were effectively born by the Ti2AlN reinforcement, the main tribological mechanism changed from adhesive wear to abrasive wear compared with Cu, thus the friction and wear resistance was also obviously improved.

Micro-Drilling of Sapphire Using Electro Chemical Discharge Machining

“…The tool electrode used in this research was made from tungsten carbide powder and cobalt powder binder through the powder metallurgic method. The melting point of the cobalt element is 1768 K, the melting point of tungsten carbide is 3143 K, and the plasma temperature of the spark discharge during the machining process is higher than 5000 K [13]. Consequently, the powder metallurgic structure of the electrode becomes loose during the machining process such that the tungsten carbide is lost.…”

“…As sapphire has the characteristics of non-electrical conductivity and cannot be cut easily [10], the present machining methods adopted in the industry, such as abrasive machining [11], laser machining [12], ultrasonic machining [13], and chemical etching techniques [14], all have certain drawbacks and limitations. The use of laser machining and ultrasonic machining methods to perform micro-machining on glass can cause the problems of surface cracks, degradation of the surface cleanliness, etc.…”