Diamond Ground Products is an expert in the field of fabricating and machining tungsten-copper. With their state-of-the-art equipment and experienced staff, DGP offers unmatched quality and capability at the lowest prices. DGP provides precise and consistent parts from low volume prototype to high-volume production and from the simplest rods to complex fabrications with the strictest tolerances.
Tungsten-Copper is a high-performance material for the manufacture of parts, and is characterized by:
High thermal conductivity
Low thermal expansion
High wear resistance
Excellent electrical conductivity
Common Tungsten Copper Applications include:
Resistance welding
Heat sinks
Electrical discharge machining
Electro-chemical machining
Electrical contacts
Contact Diamond Ground Products to see which material is right for your application and to get your FREE quote today.
2013年9月12日星期四
Why Copper Tungsten?
If you've been reading the past few posts on the use of Copper Tungsten for Electrical Discharge Machining (EDM) electrodes, you know by now that the success of the process is largely influenced by both workpiece and electrode material properties.
Accordingly, choosing an electrode material ultimately depends on its ability to interact productively with your workpiece material, as well as on your particular production goal (e.g., cost savings? surface finish? improved wear resistance?).
There are several common metrics for measuring the success of your EDM production job:
EWR (electrode wear ratio),
MRR (material removal rate) and
Ra (surface finish).
So far we've discussed how copper tungsten can improve EWR both because of its innate structural integrity as derived from both Copper and Tungsten, and because of its resistance to DC Arcing--a common EDM related frustration.
This post is all about Material Removal Rates. MRR, or cutting speed, is largely dependent on the interaction between material properties and machining parameters.
Material Properties of Copper Tungsten
Copper with its excellent thermal conductivity, is the portion of the CuW composition that drives cutting speed. This begs the question: "Why not use a pure Copper electrode then?" The answer is that Electrolytic (pure) copper poses enormous challenges in manufacturability and wear rates. But, as you may have guessed, alloying it with Tungsten improves both conditions dramatically producing a better overall performance.
Interestingly, the addition of Tungsten to Copper often generates a recast layer, commonly referred to as "black layer," during the EDM process which can actually improve wear resistance. However the additional build up slightly lowers thermal conductivity and ultimately reduces the MRR.
EDM Process Parameters to Improve MRR
Because EDM is a thermal process one would logically infer that increasing thermal conductivity will increase MRR. But material removal rate is only one of three interdependent variables listed above. In reality, it's a bit more of a "Goldilocks" problem; there is a "just-right" solution where conductivity is high enough to improve cutting rates, but not so high as to leave the spark gap empty of heat. The material lends itself to a kind of process parameter sweet spot that can produce on spec parts, incredibly efficiently. And luckily, there are many really smart people who have developed empirical models for determining process parameters, as they relate to material properties.
And more crucially, studies have shown that thermal conductivity, alone, does not influence MRR, but the combination of copper tungsten's thermal conductivity and peak current does--the direct correlation being a stronger, more impactful spark makes for fast (albeit not pretty) material removal. (Note: Just increasing peak current without also increasing conductivity, compromises surface finish because of the more explosive, uneven burn.) More specifically, the influence of thermal conductivity is realized only in conjunction with peak current.
To find out more about Copper Tungsten and why you might choose for your EDM related applications, download our free white paper!
Accordingly, choosing an electrode material ultimately depends on its ability to interact productively with your workpiece material, as well as on your particular production goal (e.g., cost savings? surface finish? improved wear resistance?).
There are several common metrics for measuring the success of your EDM production job:
EWR (electrode wear ratio),
MRR (material removal rate) and
Ra (surface finish).
So far we've discussed how copper tungsten can improve EWR both because of its innate structural integrity as derived from both Copper and Tungsten, and because of its resistance to DC Arcing--a common EDM related frustration.
This post is all about Material Removal Rates. MRR, or cutting speed, is largely dependent on the interaction between material properties and machining parameters.
Material Properties of Copper Tungsten
Copper with its excellent thermal conductivity, is the portion of the CuW composition that drives cutting speed. This begs the question: "Why not use a pure Copper electrode then?" The answer is that Electrolytic (pure) copper poses enormous challenges in manufacturability and wear rates. But, as you may have guessed, alloying it with Tungsten improves both conditions dramatically producing a better overall performance.
Interestingly, the addition of Tungsten to Copper often generates a recast layer, commonly referred to as "black layer," during the EDM process which can actually improve wear resistance. However the additional build up slightly lowers thermal conductivity and ultimately reduces the MRR.
EDM Process Parameters to Improve MRR
Because EDM is a thermal process one would logically infer that increasing thermal conductivity will increase MRR. But material removal rate is only one of three interdependent variables listed above. In reality, it's a bit more of a "Goldilocks" problem; there is a "just-right" solution where conductivity is high enough to improve cutting rates, but not so high as to leave the spark gap empty of heat. The material lends itself to a kind of process parameter sweet spot that can produce on spec parts, incredibly efficiently. And luckily, there are many really smart people who have developed empirical models for determining process parameters, as they relate to material properties.
And more crucially, studies have shown that thermal conductivity, alone, does not influence MRR, but the combination of copper tungsten's thermal conductivity and peak current does--the direct correlation being a stronger, more impactful spark makes for fast (albeit not pretty) material removal. (Note: Just increasing peak current without also increasing conductivity, compromises surface finish because of the more explosive, uneven burn.) More specifically, the influence of thermal conductivity is realized only in conjunction with peak current.
To find out more about Copper Tungsten and why you might choose for your EDM related applications, download our free white paper!
Tungsten Copper Alloy
Tungsten Copper is one of numerous metal alloys sold by American Elements under the tradename AE Alloys?. Generally immediately available in most volumes, AE Alloys? are available as bar, Ingot, ribbon, wire, shot, sheet, and foil. Ultra high purity and high purity forms also include metal powder, submicron powder and nanoscale, targets for thin film deposition, and pellets for chemical vapor deposition (CVD) and physical vapor deposition (PVD) applications. American Elements produces to many standard grades when applicable, including Mil Spec (military grade); ACS, Reagent and Technical Grade; Food, Agricultural and Pharmaceutical Grade; Optical Grade, USP and EP/BP (European Pharmacopoeia/British Pharmacopoeia) and follows applicable ASTM testing standards. Typical and custom packaging is available. Primary applications include bearing assembly, ballast, casting, step soldering, and radiation shielding.
Tungsten (W) and molecular weight, atomic number and elemental symbolTungsten (atomic symbol: W, atomic number: 74) is a Block D, Group 6, Period 6 element with an atomic weight of 183.84. The number of electrons in each of tungsten's shells is [2, 8, 18, 32, 12, 2] and its electron configuration is [Xe] 4f14 5d4 6s2. Tungsten Bohr Model The tungsten atom has a radius of 139 pm and a Van der Waals radius of 210 pm. Tungsten was discovered by Torbern Bergman in 1781 and first isolated by Juan José Elhuyar and Fausto Elhuyar in 1783. In its elemental form, tungsten has a grayish white, lustrous appearance.Elemental Tungsten Tungsten has the highest melting point of all the metallic elements and a density comparable to that or uranium or gold and about 1.7 times that of lead. Tungsten alloys are often used to make filaments and targets of x-ray tubes. It is found in the minerals scheelite (CaWO4) and wolframite [(Fe,Mn)WO4]. In reference to its density, Tungsten gets its name from the Swedish words "tung" and "sten," meaning heavy stone. For more information on tungsten, including properties, safety data, research, and American Elements' catalog of tungsten products, visit the Tungsten Information Center.
Copper Bohr ModelCopper (Cu) atomic and molecular weight, atomic number and elemental symbolCopper (atomic symbol: Cu, atomic number: 29) is a Block D, Group 11, Period 4 element with an atomic weight of 63.546. The number of electrons in each of copper's shells is 2, 8, 18, 1 and its electron configuration is [Ar] 3d10 4s1. The copper atom has a radius of 128 pm and a Van der Waals radius of 186 pm. Copper was first discovered by Early Man prior to 9000 BC.In its elemental form, copper has a red-orange metallic luster appearance. Elemental Copper Of all pure metals, only silver has a higher electrical conductivity.The origin of the word copper comes from the Latin word 'cuprium' which translates as "metal of Cyprus." Cyprus, a Mediterranean island, was known as an ancient source of mined copper. For more information on copper, including properties, safety data, research, and American Elements' catalog of copper products, visit the Copper Information Center.
Tungsten (W) and molecular weight, atomic number and elemental symbolTungsten (atomic symbol: W, atomic number: 74) is a Block D, Group 6, Period 6 element with an atomic weight of 183.84. The number of electrons in each of tungsten's shells is [2, 8, 18, 32, 12, 2] and its electron configuration is [Xe] 4f14 5d4 6s2. Tungsten Bohr Model The tungsten atom has a radius of 139 pm and a Van der Waals radius of 210 pm. Tungsten was discovered by Torbern Bergman in 1781 and first isolated by Juan José Elhuyar and Fausto Elhuyar in 1783. In its elemental form, tungsten has a grayish white, lustrous appearance.Elemental Tungsten Tungsten has the highest melting point of all the metallic elements and a density comparable to that or uranium or gold and about 1.7 times that of lead. Tungsten alloys are often used to make filaments and targets of x-ray tubes. It is found in the minerals scheelite (CaWO4) and wolframite [(Fe,Mn)WO4]. In reference to its density, Tungsten gets its name from the Swedish words "tung" and "sten," meaning heavy stone. For more information on tungsten, including properties, safety data, research, and American Elements' catalog of tungsten products, visit the Tungsten Information Center.
Copper Bohr ModelCopper (Cu) atomic and molecular weight, atomic number and elemental symbolCopper (atomic symbol: Cu, atomic number: 29) is a Block D, Group 11, Period 4 element with an atomic weight of 63.546. The number of electrons in each of copper's shells is 2, 8, 18, 1 and its electron configuration is [Ar] 3d10 4s1. The copper atom has a radius of 128 pm and a Van der Waals radius of 186 pm. Copper was first discovered by Early Man prior to 9000 BC.In its elemental form, copper has a red-orange metallic luster appearance. Elemental Copper Of all pure metals, only silver has a higher electrical conductivity.The origin of the word copper comes from the Latin word 'cuprium' which translates as "metal of Cyprus." Cyprus, a Mediterranean island, was known as an ancient source of mined copper. For more information on copper, including properties, safety data, research, and American Elements' catalog of copper products, visit the Copper Information Center.
2013年8月22日星期四
Tungsten Copper Dart
Today's standard material of tungsten barrel is Tungsten-Nickel-Iron. Tungsten is a very dense material, so darts with a considerable weight can be made quite slim. However, before the tungsten revolution darts were mainly made of brass. Not only has the density of tungsten and anti-corrosion, while a brass color, copper tungsten darts has become the best choice for many people.
Tungsten copper dart is a much softer material. To show the color of brass, they generally with about 70%~80% Tungsten content. Some darters, especially old-timers, like the grip of these darts as the metal surface develops microscopic pits after they have been thrown for a while. Tungsten copper dart has become much less common in recent years, with Nickel/Tungsten darts becoming the primary type of high-density darts.
To make the game of darts successful there is dart equipment involved. It includes dartboards, shafts, dart, barrels, flights and other accessories. Today, there are many companies that manufacture dart equipment with international standards. The dartboard used internationally is also called a “clock face” dartboard, and it is made of rope fiber that is compressed under tremendous pressure. The surface is made smooth and screen-printed with different types of color combinations. Lastly, with the help of wires and stapled rings, it is given radial movement. Darts or barrels are cylindrical, pointed equipments that are thrown by hand onto the dartboard.
There are different types of material that darts are made of. They are brass, tungsten/silver, copper, etc. Usually, three darts make a set. Flights are the tails or wings of the darts that help to stabilize the movement. These flights are made of different material like soft and hard flights, and nylon and dimplex or ribtex flights. Shafts support the body of the darts and can be made of plastic, composite, spinning and solid aluminum shafts. The dartboard and darts are hard-core dart equipment, whereas, the shafts and the flights are dart accessories.
Tungsten copper dart is a much softer material. To show the color of brass, they generally with about 70%~80% Tungsten content. Some darters, especially old-timers, like the grip of these darts as the metal surface develops microscopic pits after they have been thrown for a while. Tungsten copper dart has become much less common in recent years, with Nickel/Tungsten darts becoming the primary type of high-density darts.
To make the game of darts successful there is dart equipment involved. It includes dartboards, shafts, dart, barrels, flights and other accessories. Today, there are many companies that manufacture dart equipment with international standards. The dartboard used internationally is also called a “clock face” dartboard, and it is made of rope fiber that is compressed under tremendous pressure. The surface is made smooth and screen-printed with different types of color combinations. Lastly, with the help of wires and stapled rings, it is given radial movement. Darts or barrels are cylindrical, pointed equipments that are thrown by hand onto the dartboard.
There are different types of material that darts are made of. They are brass, tungsten/silver, copper, etc. Usually, three darts make a set. Flights are the tails or wings of the darts that help to stabilize the movement. These flights are made of different material like soft and hard flights, and nylon and dimplex or ribtex flights. Shafts support the body of the darts and can be made of plastic, composite, spinning and solid aluminum shafts. The dartboard and darts are hard-core dart equipment, whereas, the shafts and the flights are dart accessories.
Tungsten Copper Dart Barrel
Tungsten copper dart is made of the material of tungsten copper alloy. Tungsten copper alloy has the features of tungsten and copper ,which is a very dense material and it has a good machinability, so it is a good choice to make as a slim tungsten cooper dart to give user a safe and easy grip. The tungsten copper dart barrel is the main part of a tungsten copper dart. When we are speaking of "buying a (new) dart" we mean getting a new dart barrel. Nowadays barrels are available in almost every possible shape, with a wide selection of knurl or rings on the surface for a comfortable and safe grip.
Because of technical difficulties with manufacturing 100% tungsten dart barrels are not available. All "tungsten" darts you can buy are in fact made of tungsten alloys, actually now a dart made of tungsten copper alloy is becoming more and more popular among all kinds of the customers and many manufacturers.
We are specializing in supplying all kinds of tungsten copper dart barrels. We can offer various range of tungsten copper barrels, including W-Ni-Fe, W-Ni-Cu, W-Ni-Cu-Fe, etc. Also we own mature technique of surface grinding and centre-less processing. We can also manufacture darts according to customers' specific designs.
Because of technical difficulties with manufacturing 100% tungsten dart barrels are not available. All "tungsten" darts you can buy are in fact made of tungsten alloys, actually now a dart made of tungsten copper alloy is becoming more and more popular among all kinds of the customers and many manufacturers.
We are specializing in supplying all kinds of tungsten copper dart barrels. We can offer various range of tungsten copper barrels, including W-Ni-Fe, W-Ni-Cu, W-Ni-Cu-Fe, etc. Also we own mature technique of surface grinding and centre-less processing. We can also manufacture darts according to customers' specific designs.
2013年8月15日星期四
Profiting from misery in Katanga
I have just left Katanga in eastern Democratic Republic of the Congo (DRC), where my colleague Lisa Tassi and I were following up on Amnesty International’s work on mining and human rights in the region.
In some ways this is easy to do. Besides mining – mostly of copper and cobalt – precious little happens in southern Katanga. But two very different methods are employed to extract these minerals. Industrial mining, involving large multinational companies, is managed from air-conditioned offices and carried out with heavy equipment; small-scale artisanal mining is frequently done in sweltering heat by men (and in some cases boys under the age of 18) working with basic tools.
Artisanal mining can be a desperate business. On top of suffering harsh work conditions, many creuseurs – meaning “diggers”, as the miners are known locally – are ruthlessly exploited by traders who buy from them along a largely opaque supply chain. In theory the state has some oversight of the system, but the reality is quite different.
Earlier this year Amnesty International published a report exposing the horrendous conditions at an artisanal mining site in Katanga called Tilwezembe. One of the things we tried to unravel on our return visit is where minerals from sites such as Tilwezembe actually end up. Traders are key to that process.
But the supply chain to take the minerals mined by creuseurs out of Katanga is complex. It operates with virtually no oversight, and no meaningful paper trail to enable minerals to be tracked from source to export.
Katanga’s mineral traders include individuals who buy and sell as well as separate trading companies, some of which also process ore. In some cases, creuseurs work at mine sites controlled by these trading companies. The state (or the state mining company, Gécamines) gives these companies control, but seems to impose few safeguards. And so the creuseurs working the site – often through a deal between the trader and an artisanal mining cooperative – are obliged to sell directly to the trading company, with no system in place to ensure they get a fair price.
Creuseurs, who may work underground for many hours each day, regularly report that they feel cheated by this system where they have to take what they are offered with no way to challenge the traders. Because they must survive, they have no choice but to accept these unfair terms of business.
There is also very little done to ensure safety at the artisanal mine sites, and every year scores of creuseurs are killed or seriously injured. Although SAESSCAM – the government agency charged with training and assisting artisanal miners – is generally present at these sites, it has insufficient resources and limited power.
We have been trying this last week to find out what happens to the copper and cobalt that is mined in such terrible conditions. Much of it goes to China, but who buys it and can we talk to them? The answer is no, because Katanga’s byzantine trading pipeline makes it almost impossible to track ore as it changes hands from an artisanal mine site to a trader to a processor and on to export, let alone track it to the final destination.
In Kolwezi, a centre for much of the copper and cobalt trade, we visited a depot where dozens of traders (Congolese and foreign) buy from creuseurs who arrive with sacks of minerals on bikes. Some of the creuseurs tell us that no questions are asked here – they bring, they sell; no-one who buys from them knows where the ore comes from. They do not, themselves, have any way to measure the concentration of the ore they have mined. And so they accept the price. But they tell us that here, at least, they are free to offer their ore to a range of traders and sell to the highest bidder.
By contrast, creuseurs working on sites controlled by trading companies face a monopoly. One man we met at the Kolwezi depot told us he worked on a site controlled by a trader and had smuggled out some ore to sell at the depot, as the price on site was too little for the hours of work and he felt he was not getting a fair deal.
We talked to some of the buyers at one of the depot’s many trading stalls – in this case a group of Chinese and Congolese who had erected a makeshift desk, and had a scale, a calculator and a box of cash. They were none too happy to see us, and they politely – but firmly – evaded our queries about where the ore comes from and goes to. It comes from all over Katanga and goes to various processing companies, they say. There is no paperwork that we can see – and when we ask about a paper trail, the traders will not answer.
The traders sell to others inside Katanga where the ore is processed (or not) before being sent out of the country, often by the truckload across the Zambian border. Export paperwork gets filled out and filed, but by this stage in the process the origin of the minerals has already been obscured.
The life of a creuseur is harsh. The Congolese authorities can – and must – do more to protect people from exploitative and harmful working conditions. But those who buy the ore along the supply chain can also make a difference, if they insist on knowing from which sites the ore or minerals come and the conditions on site and the conditions under which it continues to be traded. Key questions need to be asked and information verified. However, this kind of due diligence is impossible if there is no proper recording and oversight, and if traders can buy and export without anyone being able to tell if the minerals are extracted in appalling conditions.
In other parts of the DRC, including the Kivus, Maniema and northern Katanga, a system has been put in place for tracing tin, tantalum, tungsten and gold, and building documentation. If it can be done in these areas, then why not extend the programme to Katanga’s cobalt and copper sector?
Efforts to ensure fair work conditions for creuseurs have to take account of the fact that there is practically no other livelihood on offer to many Katanga residents. The answer is not to prevent artisanal mining but to make it a safer and fairer business until longer-term solutions are found.
In some ways this is easy to do. Besides mining – mostly of copper and cobalt – precious little happens in southern Katanga. But two very different methods are employed to extract these minerals. Industrial mining, involving large multinational companies, is managed from air-conditioned offices and carried out with heavy equipment; small-scale artisanal mining is frequently done in sweltering heat by men (and in some cases boys under the age of 18) working with basic tools.
Artisanal mining can be a desperate business. On top of suffering harsh work conditions, many creuseurs – meaning “diggers”, as the miners are known locally – are ruthlessly exploited by traders who buy from them along a largely opaque supply chain. In theory the state has some oversight of the system, but the reality is quite different.
Earlier this year Amnesty International published a report exposing the horrendous conditions at an artisanal mining site in Katanga called Tilwezembe. One of the things we tried to unravel on our return visit is where minerals from sites such as Tilwezembe actually end up. Traders are key to that process.
But the supply chain to take the minerals mined by creuseurs out of Katanga is complex. It operates with virtually no oversight, and no meaningful paper trail to enable minerals to be tracked from source to export.
Katanga’s mineral traders include individuals who buy and sell as well as separate trading companies, some of which also process ore. In some cases, creuseurs work at mine sites controlled by these trading companies. The state (or the state mining company, Gécamines) gives these companies control, but seems to impose few safeguards. And so the creuseurs working the site – often through a deal between the trader and an artisanal mining cooperative – are obliged to sell directly to the trading company, with no system in place to ensure they get a fair price.
Creuseurs, who may work underground for many hours each day, regularly report that they feel cheated by this system where they have to take what they are offered with no way to challenge the traders. Because they must survive, they have no choice but to accept these unfair terms of business.
There is also very little done to ensure safety at the artisanal mine sites, and every year scores of creuseurs are killed or seriously injured. Although SAESSCAM – the government agency charged with training and assisting artisanal miners – is generally present at these sites, it has insufficient resources and limited power.
We have been trying this last week to find out what happens to the copper and cobalt that is mined in such terrible conditions. Much of it goes to China, but who buys it and can we talk to them? The answer is no, because Katanga’s byzantine trading pipeline makes it almost impossible to track ore as it changes hands from an artisanal mine site to a trader to a processor and on to export, let alone track it to the final destination.
In Kolwezi, a centre for much of the copper and cobalt trade, we visited a depot where dozens of traders (Congolese and foreign) buy from creuseurs who arrive with sacks of minerals on bikes. Some of the creuseurs tell us that no questions are asked here – they bring, they sell; no-one who buys from them knows where the ore comes from. They do not, themselves, have any way to measure the concentration of the ore they have mined. And so they accept the price. But they tell us that here, at least, they are free to offer their ore to a range of traders and sell to the highest bidder.
By contrast, creuseurs working on sites controlled by trading companies face a monopoly. One man we met at the Kolwezi depot told us he worked on a site controlled by a trader and had smuggled out some ore to sell at the depot, as the price on site was too little for the hours of work and he felt he was not getting a fair deal.
We talked to some of the buyers at one of the depot’s many trading stalls – in this case a group of Chinese and Congolese who had erected a makeshift desk, and had a scale, a calculator and a box of cash. They were none too happy to see us, and they politely – but firmly – evaded our queries about where the ore comes from and goes to. It comes from all over Katanga and goes to various processing companies, they say. There is no paperwork that we can see – and when we ask about a paper trail, the traders will not answer.
The traders sell to others inside Katanga where the ore is processed (or not) before being sent out of the country, often by the truckload across the Zambian border. Export paperwork gets filled out and filed, but by this stage in the process the origin of the minerals has already been obscured.
The life of a creuseur is harsh. The Congolese authorities can – and must – do more to protect people from exploitative and harmful working conditions. But those who buy the ore along the supply chain can also make a difference, if they insist on knowing from which sites the ore or minerals come and the conditions on site and the conditions under which it continues to be traded. Key questions need to be asked and information verified. However, this kind of due diligence is impossible if there is no proper recording and oversight, and if traders can buy and export without anyone being able to tell if the minerals are extracted in appalling conditions.
In other parts of the DRC, including the Kivus, Maniema and northern Katanga, a system has been put in place for tracing tin, tantalum, tungsten and gold, and building documentation. If it can be done in these areas, then why not extend the programme to Katanga’s cobalt and copper sector?
Efforts to ensure fair work conditions for creuseurs have to take account of the fact that there is practically no other livelihood on offer to many Katanga residents. The answer is not to prevent artisanal mining but to make it a safer and fairer business until longer-term solutions are found.
Tungsten Copper Machining
The principal Tungsten/Copper alloys contain from 2% to 45% copper by weight. The addition of copper increases the thermal conductivity of the alloy while reducing the hardness and modulus of rupture.
The machining and grinding characteristics of tungsten/copper alloys are similar to those of hard grey cast iron. Being non-porous, standard water soluble coolants may be used if desired, but are not required. Each machine shop usually has its individual machining or grinding practice and, therefore, the information presented should be considered as a guide only.
Tool: Carballoy, grade 883 or equivalent. Grind tools with 0 deg. rake, 8-12 deg. clearance, and .010" to .025" nose radius. The nose radius can increase with the size of the work. For fine finish, stone small flat on tool parallel to work. Suggest resting stone on work when honing tool.
Turning & Boring: Roughing, approximately .030" deep and .020" per revolution feed. Finishing, .002" to.005" depth of cut and .001" to .002" per revolution feed. Turning speed, 300-500 surface feet per minute. Do not use lubricant or coolant.
Shaping: Tool Speed: 43" per minute for Tungsten-Copper 25% alloy.
Depth of Cut: .030"
Feed: .020" per stroke
Milling: Drilling High Speed steel drills and taps may be used.
Through Tapping: Holes are recommended. Material must be firmly held. Hand feed-lubricant and cutting oil acceptable.
Rough Grinding: Is best done with 80 grit resin bonded wheels of medium hardness; .015" per pass on Tungsten-Copper 25% alloy. Use water or water soluble oil coolant.
Joining: Material may be silver brazed, or copper brazed in a hydrogen atmosphere.
We hope the preceding information will be helpful.
The machining and grinding characteristics of tungsten/copper alloys are similar to those of hard grey cast iron. Being non-porous, standard water soluble coolants may be used if desired, but are not required. Each machine shop usually has its individual machining or grinding practice and, therefore, the information presented should be considered as a guide only.
Tool: Carballoy, grade 883 or equivalent. Grind tools with 0 deg. rake, 8-12 deg. clearance, and .010" to .025" nose radius. The nose radius can increase with the size of the work. For fine finish, stone small flat on tool parallel to work. Suggest resting stone on work when honing tool.
Turning & Boring: Roughing, approximately .030" deep and .020" per revolution feed. Finishing, .002" to.005" depth of cut and .001" to .002" per revolution feed. Turning speed, 300-500 surface feet per minute. Do not use lubricant or coolant.
Shaping: Tool Speed: 43" per minute for Tungsten-Copper 25% alloy.
Depth of Cut: .030"
Feed: .020" per stroke
Milling: Drilling High Speed steel drills and taps may be used.
Through Tapping: Holes are recommended. Material must be firmly held. Hand feed-lubricant and cutting oil acceptable.
Rough Grinding: Is best done with 80 grit resin bonded wheels of medium hardness; .015" per pass on Tungsten-Copper 25% alloy. Use water or water soluble oil coolant.
Joining: Material may be silver brazed, or copper brazed in a hydrogen atmosphere.
We hope the preceding information will be helpful.
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