Diamonds for Dressing Tools
Natural Diamonds are the most effective and efficient material for the dressing of conventional grinding wheels. This is primarily true because of the formation of natural diamond and the vast range of qualities available. Firstly, the shape…the octahedron and dodecahedral structure with closed edges which come together to form the strong points required for single point dressing applications cannot be substituted competitively. Additionally, each diamond, because of its natural geometry, can have as many as six usable points. Users can opt for a range of tools from single use tools, with a stone having only one useable point, to tools with stones which can be re-set to use all 6 of the available points. The fact that it is a single crystal adds to the diamonds structural integrity, giving continuous dressing action while maintaining strength throughout its life. By choosing the correct size, quality, and number of settable points, the end user will be able to dress the wheels properly and obtain the best productivity at the lowest cost.
We can look at a few examples that will illustrate how the application dictates which type of diamond should be used. For dressing thread grinders, very sharp points and angles are required to enter the narrow grooves on the wheel; clearly, the design of the tool calls for octahedral or even sharper crystal type diamonds. This gives the operator the ability to dress very sharp angles. For high production situations, the design will call for a high quality stone that will hold up under repetitive use. For lower levels of productions, the user may save on cost by using an appropriately chosen, lower priced stone.
For wheels made of materials tougher than standard abrasives, such as the ceramic wheels used in some very tough applications, a dodecahedral shaped diamond offers great strength and durability. There is more material surrounding the point of a dodecahedral than the point of an octahedral, consequently reducing the wear rates. The experienced diamond tool manufacturer understands the need for a stone with significant durability and designs the tool based upon this criterion. The number of usable points as well as the overall quality of the stone will be a function of the expected workload.
There are other types of dressing tools that use multiple stone configurations to obtain the advantage of natural diamond in dressing applications. Elongated materials can be set up in various configurations for specialized blade tools. Lower priced diamonds may be used in various types of "cluster tools", even lower priced Congo cubes and rounds as well as other low range materials are in demand for inexpensive "throw away" type tooling.
All of this shows that there is great flexibility in natural diamond dressing tools, from the standpoint of performance as well as cost. For dressing applications, natural diamond has the characteristics that make it the preferred material.
Diamonds for Form Tools For Truing and Dressing Applications
Although Polycrystalline diamonds as well as single crystal synthetics have impacted this market, natural diamond remains a prominent player.
The tool designer who works with natural diamonds has a great variety of formation, size and quality of natural diamonds from which to choose. Let us look at the various natural formations available:
Form dressers are designed for truing and dressing formed grinding wheels. The tolerances of the tool are critical to obtain good manufacturing processes. Ultra fine, clean diamonds are selected and polished by skilled diamond cutters to precise tolerances for the most critical applications.
Medium quality diamonds may be chosen and cut to acceptable tolerances when the design calls for less stringent specifications yet requiring a tool that stands up under high production conditions. Lower quality diamonds are called for in the design of typical, utility type tools. In these situations, cost of the stone may be the over riding factor; however, the requirements of a superabrasive tool can still be met with a quality product when the diamond form, size and quality are correctly matched to the application.
This area of application is clearly the one which has been most affected by man made products and other new technologies. The effect has been positive in that the availability of many types of superabrasive products has broadened the field of usage and expanded the overall superabrasive cutting tool market throughout the world.
PCD, PCBN, Single Crystal Synthetics and CVD products all have proven effective in many new as well as traditional areas for cutting tool applications. Nonetheless, manufacturers and users still find a broad range of applications where natural diamond is the optimum product. The finished cutting edges of PCD, PCBN and CVD products are inherently limited by the fact that they are multi particle products. CVD products have, so far, also been limited in their maximum thickness as well as limited by problems with adherence to the substrate.
Both natural diamonds and single crystal synthetics are used where high magnification, chip free cutting edges are required. Yet, the use of single crystal synthetics may sometimes be questionable, as many end users have determined that tool life may be inconsistent and that natural diamond, under similar conditions, will outperform single crystal synthetics. The available range of quality, size, shape, thickness and other characteristics found in natural diamonds gives great flexibility and choice to the end user and the tool designer. The "one quality, one price" of synthetics tends to limit the end users choice.
Again, we see that in many applications, natural diamond is the product of choice.
Diamond Dies for Drawing Wire
In every conceivable application from electronics to construction, wiredrawing dies are the essential tools used to produce the billions of miles of wire drawn throughout the world. For applications of drawing non-ferrous metals, which require ultra fine finishes, diamonds are used as the cutting, or drawing material. In particular, in today’s high tech world, ultra fine wires are required in enormous quantities and the demand for diamond dies has exceeded the expectations of many.
In fact, it was believed that the advent of PCD and single crystal synthetics would eliminate the demand for natural diamond. Although single crystal synthetics have been on the market for a few years now, and have entered some niche markets, producers, end users and suppliers continue to have strong demand for natural diamond dies. PCD has helped to expand the market for diamond dies replacing carbide dies for larger sizes and improving productivity dramatically. The continuing demand for natural diamond stones can be directly related to better performance from naturals plus the great flexibility in pricing and sizing that naturals provide. For obtaining high finish and for drawing fine sizes, natural diamond continues to be the material of choice offering the highest quality with the greatest productivity.
In some cases where PCD had made great in-roads, particularly for larger size dies, natural diamonds have made a comeback. In certain applications, some materials present in PCD have caused problems during the wire drawing process. One example of this is "sparking", which can cause the lubricants to ignite. This of course translates into down time and losses. The purity of natural diamond and its single crystal structure are the important characteristics allowing it to work unhindered in these applications. The revival of demand for larger size natural die-stones is effectively the result of definitive problems that arose in the use of alternative products.
For the making of natural diamond dies, the wire die manufacturer selects a high quality diamond, flattens both sides with parallel faces, sets the stone in a hard metal blank, drills through and polishes the center of the stone creating the critical form and tolerances required by the wire manufacturer. Of course, this is a serious over simplification of a complex and critical process. With natural diamond dies, the producer will design the tool based on the size and type of wire to be finished, enabling them to determine the dimensions of the stone required. The diamond must be clean and uniform. Other characteristics will be taken into account when the toolmaker is selecting the appropriate diamond. This is individual to the company’s process and adds flexibility of price according to the specifications of the application. With this, the die maker can be highly competitive, tailoring products to meet the demands of their customers. In turn, this enables the wire producer to meet the needs of industry at the most cost-effective levels while ensuring high quality products.
We are confident that, for the wire die industry, natural diamond dies are well suited to meet industry demands and will continue as an essential superabrasive material for many years to come.
Diamonds for Drill Bits
Diamond drill bits are used in mineral and oil exploration, mining, and construction. They are an excellent example of products that achieve results possible only with superabrasives.
Whether searching for minerals and metals, or, tapping the great oil reserves of the world, diamond bits are used to drill through the rugged earth efficiently, reducing expensive downtime for drill rigs. In the construction industry, where repetitive drilling of hard materials is commonplace, diamond drill bits are normally used. Prior to the early 1980’s, natural diamond stones were used in surface set bits for exploration and mining. These bits are made by hand setting select diamonds in a mold, which is then filled with powdered metal and heated to form the diamond bit. The bits are then used, and a process started which involves reclaiming the natural diamond from used bits, resetting the usable stones, and returning the bit to the user. The entire process, from hand setting to reclaiming used bits, to the bookkeeping for diamond reclamation, is an expensive process. Consequently, most hand set bits were replaced with either PCD blanks or bits made with either natural or synthetic mesh.
This is clearly an area where the usage of natural diamonds has been heavily affected; however, natural diamonds continue to be used, although at a lower level of consumption and price than in the days before alternative products were available. The availability of inexpensive natural diamonds allows bit manufacturers to exploit the potential of naturals by using naturals exclusively or mixed with synthetic products. Thus, manufacturers can produce bits that increase the efficiency of the drilling process.
In exploration and mining, the drilling conditions determine whether whole natural stones or processed diamonds are used. In construction, impregnated bits are made utilizing natural as well as synthetic mesh.
For the drill industry as a whole, the use of natural industrial diamond continues to be important in achieving maximum productivity levels.
Grinding Wheels, Rotary Dressers, Impregnated Tools
This group of tools is used in many types of engineering applications. Natural diamond is often the raw material of choice when manufacturing various types of impregnated tooling used in dresser applications. The strength of the natural crystal and the cutting and friability properties of natural diamond, provide the best characteristics in many of these applications. Consequently, in manufacturing rotary dressers, natural diamonds, both processed and unprocessed, are the main material used. Where additional strength is required, such as in critical sections of the rotary dresser, natural diamond crystals are used to give added strength to the wheels.
Natural diamond powders are used to obtain ultra fine finishes and for fine grinding. The producers of these natural materials process, crush, categorize and size each product into the many grades, which are used in today’s Superabrasives industry.
Diamonds for Specialized Applications
Diamonds are intrinsic to the manufacture of certain types of high precision
tools and knives. The single crystal continuous structure, combined with the
purity, stability, strength and integrity of natural diamond provides the best
possible choice of material for use in new and evolving technology. Diamond
knives are used in surgical procedures and for slicing and sampling of various
materials, including human tissue. Diamond nozzles are used in water jets for
specialized cutting applications. In high-tech industries such as the
manufacture of fiber optic lines as well as certain precise etching
applications, no other material has the repeatable characteristics of natural
diamonds. Heat sinks, specialized diamond windows, guides, hardness testers, and
ultra precision cutting tools are but a few more of the specialized applications
where natural diamonds excel. If more attention and thought is applied to this
field, surely tool manufacturers will be able to extend and increase the range
of tools made with natural diamonds.
Natural diamond is a modern product for building the future!