Features Resin Bond Should Have When Applied in Diamond Tools
December 15th, 2009
When resin is used in diamond tools as the bond material, some approaches should be adopted to make it have below features:
When resin is used in diamond tools as the bond material, some approaches should be adopted to make it have below features:
Earlier diamond segments of diamond circular blades were all designed to be even cuboids. Later, people found that, after a period of sawing, the two sides of the segments are easier to be worn than the middle, and the segments become a convex shape. The convex-shape diamond segments have a larger contact area with the material being cut, therefore the diamonds on them are easier to be ground blunt and then need dressing. In addition, as the sawing force will also increase, the core of the diamond blade tends to be distorted and be deformed for vibrations. This can influence the cutting precision, and reduce the blade core’s service life. Sandwich diamond segments, which have higher side layers and lower middle layers, however, can solve this problem to a great extent.
The shape of diamond segments is an important factor influencing the performance of diamond saw blades. The different shapes are directly related to cutting efficiency and the ratio of the diamonds’ non-normal failure.
A diamond blade consists of a steel core and some diamond segments. In many cases, a diamond segment (especially for those diamond segments for laser welding) includes not only a working layer (containing diamonds for cutting), but also a transition layer. The transition layer has no diamonds, and is a pure bond layer which connects the working layer to the steel core of a diamond blade.
The valid working parts of metal-bonded diamond tools (e.g., the teeth of the common diamond blades) are normally called diamond segment, which is the sintered mixture of diamond grains and metal bond materials. Generally, diamond segments are made via the procedures of mixing diamond grains with bond materials, hot pressing and sintering, and arc grinding. They can be arc-shaped or rectangular.
There are two kind rims of diamond circular saw blades: continuous and segmented. Continuous rim diamond circular saw blades can cut smoothly with less material chips, while all the welded diamond circular blades and especially the ones whose diameter are bigger than 400 mm adopt the cores with segmented rim, on which diamond segments can be more easily welded.
Normally, diamonds (synthetic or natural) for industrial uses are small-size grains, and are difficult to be directly used as tools. They are usually fixed on the valid working parts of a tool via some kinds of bond materials or by some other special means to form a kind of tool, which has a certain shape, strength and uses. These tools are normally called diamond tools.
Resin bonded diamond grinding tools are made by using diamonds as the abrasive and resin powder as the adhesive, and adding some proper fillers such as copper powder. After being prepared, mixed, hot-pressed to a certain shape, cured and machined, these materials can then be changed into final products. An example of resin bonded diamond grinding tool is the diamond polishing pads, which are used for polishing stone, concrete, glass, etc.
There are many methods to manufacture diamonds in the world, but the most common method is static high-pressure high-temperature synthesis with catalysts. According to the characteristics of the synthesis technology and the crystal growth mechanism, these methods can be categorized to the following types:
Perhaps diamond is the hardest material on the earth (it is said that there are still some harder materials). It has high thermal conductivity, high insulation and high chemical stability. It can be used to process non-ferrous metals such as aluminum and copper both efficiently and precisely, and is especially suitable to process hard and brittle non-metallic materials.