Composition of Diamond Wire Saw

A diamond wire saw consists of a specific number of diamond beads strung in proportion along a multi-strand steel cable. Adjacent beads are separated by spacers that provide support and fixation. The steel cable is characterized by its high tensile strength and resistance to breakage. To increase the tensile strength, the steel cable is continuously wound. The diamond beads, shaped into rings, are fixed at evenly spaced intervals on the outer side of the cable using materials such as rubber, plastic, or springs. The final product, called a diamond wire saw, is a complete assembly made of a flexible steel cable, diamond beads, and connecting materials (springs, rubber, etc.).

The flexible steel cable serves to connect and enhance tensile strength, while the annular diamond beads on the cable are responsible for the cutting friction during operation. Springs and rubber provide reinforcement, ensuring that the diamond beads remain securely in place.

Working Principle of Diamond Wire Saw Processing

Diamond wire saw processing is accomplished through the combined effort of the diamond bead wire, which directly participates in cutting, and the corresponding mechanical equipment (i.e., wire saw machine) that drives the bead wire's movement. Before processing, the bead wire is joined into a closed loop by using copper sleeves or other connectors to butt the ends of a certain length of bead wire together. During processing, the closed-loop bead wire is tensioned on the guide wheel set of the wire saw machine. Driven by power, the bead wire moves at high speed, and cutting is achieved through the abrasive movement of the beads.

Manufacturing Process of Diamond Beads

Process Classification: Currently, diamond beads are manufactured using electroplating and hot-press sintering methods. Recently, a brazing method for diamond beads has also been developed.

Process Comparison

(a) Electroplating Diamond Beads: Diamond is held in place by a nickel binder; only a single layer of diamond is present, resulting in fast initial cutting speeds that quickly wear down, especially when cutting hard rock. Electroplated beads are more suited for cutting softer materials like marble.

(b) Sintered Diamond Beads: Diamonds are held in place by metal binders (e.g., cobalt); these beads contain multiple layers of diamond, offering slower cutting speeds but significantly longer lifespan, ideal for cutting hard materials like granite and reinforced concrete.

(c) Brazing Diamond Beads

Issues with Both Processes

Both types of diamond beads have diamonds distributed randomly within the matrix, held mechanically. This often leads to inefficiencies as diamonds do not fully protrude, causing inadequate cutting and excessive wear due to tensile forces. Furthermore, uneven diamond distribution can result in areas of high concentration where diamonds are not fully utilized, leading to wastage and blockage of chip evacuation channels.

Advantages of Brazing Diamond Beads

With technological advancements, researchers have developed brazing methods to address the shortcomings of the previous techniques. Brazing securely holds the diamonds in place on the matrix, significantly improving the bond strength between the matrix and diamond grains. This prevents premature diamond detachment and improves cutting efficiency. The brazing method ensures uniform diamond distribution, allowing each grain to cut effectively, reducing waste, and facilitating smooth chip removal.

Applications of Diamond Wire Saw

Originally designed for quarrying and cutting stone blocks, diamond wire saws are now extensively used in construction demolition, cutting large stone blocks or concrete, and even severing large steel cables. In recent years, diamond wire saws have gained popularity in large-scale building demolition projects due to their short preparation time, flexible cutting, low noise, dust, and pollution, making them the preferred 'green' demolition tool of the 21st century. Diamond wire saw technology is expected to advance towards smaller bead diameters, saving both material and energy, with brazed diamond beads becoming the mainstream in processing.