But overall, tungsten copper electrode sintering temperature sintering property performance is more sensitive than the sintering time. The properties of tungsten copper electrode at different sintering temperature for 1h as follow:

As the sintering temperature increases, the density of tungsten skeleton also increases. While to prepare infiltrated tungsten skeleton well, on the one hand requires that tungsten skeleton has a certain hardness and strength, on the other hand requires tungsten skeleton excellent connectivity inside, which is conducive to metallic copper infiltration.

More information about sintering process effect on tungsten copper electrode properties, click here:

http://news.chinatungsten.com/en/tungsten-information/80415-ti-10319

For a certain density of compacts, sintering of tungsten skeleton is undoubtedly key processes of manufacturing tungsten copper electrode. High-temperature sintering can remove the impurities easily and ensure the electric conductivity. While the choice of the sintering temperature is mainly consider that the impact of tungsten powder granularity, particle size distribution and pressing density and other factors.

If the temperature is too low, the porosity, the hardness and density of tungsten copper electrode will decrease; If the temperature is too high, the porosity is low, the copper content is relatively reduced, high product density, electrical conductivity, and formability is deteriorated.

Therefore, under normal circumstances would control the sintering temperature range between 1600 ℃ -2200 ℃. The sintering time and the sintering temperature can be achieved relatively matched state by some adjustments to improve the sintering temperature sintering time can be shortened, thereby improving the processing efficiency, and sintering time may be extended to some extent reduce the sintering temperature.

In last part we know that the shape of brad points is important to the cut effects of tungsten carbide brad point drill bits, which requires different features for specific tasks. This part will talk about the other applications of brad point drill bits in other materials.

Tungsten carbide brad point drill bits are ordinarily available in diameters from 3–16 mm (0.12–0.63 in).Brad point drill bits work also well in most plastics, nylon, fiber, fiberglass and many other man made materials. Conventional twist drill bits in a hand drill, where the hole axis is not maintained throughout the operation, have a tendency to smear the edges of the hole through side friction as the drill bit vibrates.

In metal, the tungsten carbide brad point drill bit is confined to drilling only the thinnest and softest sheet metals in a drill press. The bits have an extremely fast cutting tool geometry: no point angle and a large (considering the flat cutting edge) lip angle causes the edges to take a very aggressive cut with relatively little point pressure. This means these bits tend to bind in metal; given a workpiece of sufficient thinness, they have a tendency to punch through and leave the bit's cross-sectional geometry behind.

(The End. This article is divided into 5 parts, and this is part 5. For part 4 please refer to http://news.chinatungsten.com/en/tungsten-information/80399-ti-10363)

In last part we know that tungsten carbide brad point drill bits have two types and the drill bits for soft wood have round outlining spurs while those for hard wood have sharp ones, and we shall not mix them up in different tasks..This part we will explain the two basic types of brad point drill bit.

Another feature of the tungsten carbide brad point drill that could affect its cutting ability is the actual brad or pyramid point in the center. Although the sole purpose of the brad point is to guide the drill through the material and keep it running straight, the shape of the brad point can affect the results. The brad itself does not actually cut the wood. It mainly scrapes and pushes the wood aside. If the base of the brad point is too thick or fat, the drill will be much harder to push especially in hardwoods. A brad that is too thin will allow the drill to cut freely but may break off in the process. It is also very important that the brad is exactly centered at the point of the drill. An off-center brad can cause a drill to cut larger than it actually measures.

We often vary the length of the brad point to achieve different results. A longer brad can be used when a hole needs to be drilled on an angle instead of straight into the wood. Drilling as much as 45 degrees or even 60 degrees from vertical is possible by extending the length of the brad. A shorter than normal brad may be required in the case of a hole that needs to be drilled close to but not through the back of the material.

(To be continued. This article is divided into 5 parts, and this is part 4. For part 3 please refer to http://news.chinatungsten.com/en/tungsten-information/80398-ti-10362; for part 5, please refer to http://news.chinatungsten.com/en/tungsten-information/80400-ti-10364)

In last part we know that the tungsten carbide brad point drill bits cut a clean hole by firstly cutting the hole periphery with outlining spurs instead of a straight chisel to avoid pulling off the wood fiber. This part we will explain the two basic types of brad point drill bit.

There are basically two types of tungsten carbide brad point designs we use. One works best in hardwoods and the other works best in softwoods. Tungsten carbide brad point drills that are specifically designed for softwood produce too much heat and are hard to push in hardwoods. Although brad point drills specifically designed to cut hardwood will cut softwood, the aggressive cutting edges have a tendency to lift the weak grains of the softwood resulting in a ragged edge around the opening of the hole. 

The difference between the two types of points is in the design of the outlining spurs. The brad point drills that work best in softwood have rounded spurs, which help to hold the grains of the wood down while sheering them off. There is a certain amount of rubbing that occurs between the outlining spur and the wood before it is cut. The outlining spurs on brad point drills for hardwood come to a sharp point and simply cut the stronger grains off clean. No rubbing occurs and therefore no unnecessary heat is produced by the cutting action.

(To be continued. This article is divided into 5 parts, and this is part 3. For part 2 please refer to http://news.chinatungsten.com/en/tungsten-information/80397-ti10361; for part 4 please  refer to http://news.chinatungsten.com/en/tungsten-information/80399-ti-10363)

In last part we know that while boring wood, tungsten carbide brad point drill bits can position precisely with its pointed tips, remove chips fast with their wide flutes, and produce accurate and clean-edged holes with the double spurs.This part we will explain further the mechanism of brad point drill bits.

Conventional twist drill bits tend to wander when presented to a flat workpiece. For metalwork, this is countered by drilling a pilot hole with a spotting drill bit. In wood, the tungsten carbide brad point drill bit is another solution: The center of the drill bit is given not the straight chisel of the twist drill bit, but a brad with a sharp point and four sharp corners to cut the wood. The sharp point of the spur simply pushes into the soft wood to keep the drill bit in line.

Metals are typically isotropic, and an ordinary twist drill bit shears the edges of the hole cleanly. Wood drilled across the grain has long strands of wood fiber. These long strands tend to pull out of the wood hole, rather than being cleanly cut at the hole edge. The tungsten carbide brad point drill bit has the outside corner of the cutting edges leading, so that it cuts the periphery of the hole before the inner parts of the cutting edges plane off the base of the hole. By cutting the periphery first, the cutting spurs maximizes the chance that the fibers can be cut cleanly, rather than having them pull messily out of the timber.

(To be continued. This article is divided into 5 parts, and this is part 2. For part 1, please refer to http://news.chinatungsten.com/en/tungsten-information/80396-ti-10360; for part 3, please refer to http://news.chinatungsten.com/en/tungsten-information/80398-ti-10362)

A tungsten carbide brad point bit is designed for boring into wood. It can provide the cleanest, straightest, and most accurately sized hole in wood of any reasonably priced tool on the market today. The brad in the center of the point allows accurate positioning when starting a hole even if the hole is not 90 degrees from the surface. The flutes — grooves that wrap around the bit and channel away chips and dust — are extra-wide to remove more material.The outlining spurs sheer the wood grain and leave a clean edge around the opening of the hole eliminating the need for sanding. The spurs continue to sheer the wood while drilling and produce an accurately sized hole. In most woods, the spurs also help to produce a cleaner edge when drilling through the backside of the wood.

(To be continued. This article is divided into 5 parts, and this is part 1. For part 2, please refer to http://news.chinatungsten.com/en/tungsten-information/80397-ti10361)

The Panzer II was the common name for a family of German tanks used in World War II. The official German designation was Panzerkampfwagen II (abbreviated PzKpfw II). Although the vehicle had originally been designed as a stopgap while more advanced tanks were developed, it nonetheless went on to play an important role in the early years of World War II, during the Polish and French campaigns. The Panzer II was the most numerous tanks in the German Panzer divisions beginning with the invasion of France, until it was supplemented by the Panzer III and IV in 1940/41. Afterwards, it was used to great effect as a reconnaissance tank.

The Panzer II was designed before the experience of the Spanish Civil War of 1936-39 showed that shell-proof armor was required for tanks to survive on a modern battlefield. Prior to that, armor was designed to stop machinegun fire and High Explosive shell fragments.

For the fragments, tungsten is a very hard brittle material that melts at over 3400 C. In fact it is virtually impossible to melt tungsten and cast it into precise shapes and it is almost impossible to machine. So tungsten precision parts are made by pressing very pure tungsten powder  in very precise molds to shape the various tungsten core so that the resulting shapes don’t need to be machined.

Most tank versions of the Panzer II were armed with a 2 cm KwK 30 55 calibers long cannon. Some later versions used the 2 cm KwK 38 L/55 which was similar. This cannon was based on the 2 cm FlaK 30 anti-aircraft gun, and was capable of firing at a rate of 280 rounds per minute, a very high rate for a tank. The Panzer II also had a 7.92 mm Maschinengewehr 34 machine gun mounted coaxially with the main gun.

The 2 cm cannon proved to be ineffective against many Allied tanks, and experiments were made towards replacing it with a 37 mm cannon, but nothing came of this. Prototypes were built with a 50 mm tank gun, but by then the Panzer II had outlived its usefulness as a tank regardless of armament. Greater success was had by replacing the standard armor-piercing explosive ammunition with tungsten cored solid ammunition, but due to material shortages this ammunition was in chronically short supply.

Compared DU, tungsten has played an integral part of the US nuclear program since the early 1940s. One of the first discussions of the use of tungsten carbide as a tamper for the U-235 gun assembly occurred during mid 1944. A series of reports were produced by Los Alamos on integral experiments that discussed tamper reflection and distributions and tungsten played a key role in those experiments.

高比重合金供应商：中钨在线科技有限公司	产品详情： http://www.tungsten-alloy.com
电话：0592-5129696 传真：5129797	电子邮件：sales@chinatungsten.com
钨钼文库：http://i.chinatungsten.com	钨钼图片： http://image.chinatungsten.com
钨新闻3G版：http://3g.chinatungsten.com	钼业新闻： http://news.molybdenum.com.cn

微信：

微博：

With the increasing compacting press, the electric conductivity of tungsten copper electrode decreases. This is due to the pressing pressure increases, the degree of plastic deformation of tungsten-copper alloy increases, including the increase of crystal defects. These defects regardless of vacancy, dislocation, grain boundaries or lattice distortion, will to some extent hindered the movement of electrons, scattering of electrons increase, which will make the resistivity of tungsten copper alloy electrodes increases the conductivity decreases.

Effect of compaction pressure on the hardness and conductivity of tungsten copper electrode as follow:

Tile or glass plates are not easy to be drilled through with a hole since the surface of the tiles have a layer of hardened material as tough as glass. An ordinary steel drill bit may fail to penetrate the tile, or cause it to shatter. Glass bits or tile bits are shaped to reduce the risk of shattering brittle materials. These should be carbide-tipped.

A tungsten carbide tile drill bits has a ground tungsten carbide tip and is used for drilling ceramic tiles and glass. The head is usually black in color. It is best to use a variable speed power drill for this bit and generally at a slow speed so that you will not crack or break the glass or tile that you are drilling into. 

When drilling into glass, it is best to use a lubricant such as turpentine or white spirit to keep the tip cool and prevent the glass from cracking or breaking. Also, drill at a slow speed into glass.When drilling into a ceramic tile, also drill at a slower speed but no liquid is needed to keep the tip cool.(The End)