Crosswords0 min ago
Artificial Diamonds and Ceramic Knives.
12 Answers
1. Artificial Diamonds.
I recently watched a programme on TV "Quest" about the manufacture of artificial diamonds (for use as jewellery) which can be produced in a few days.
The programme stated that natural diamonds come from trees which have fallen and have been crushed by rocks for thousands of years. The artificial diamonds had to be cut and polished by craftsmen in the same way as natural diamonds and although they were yellow and much larger than usual as jewellery, they were very cheap comparatively.
2.Ceramic Knives.
These are stronger than stainless steel and never need to be resharpened.
In the process of manufacture some metal particles are introduced so that they will set off scanning alarms at airports.
They are very popular with chefs, apparently.
I recently watched a programme on TV "Quest" about the manufacture of artificial diamonds (for use as jewellery) which can be produced in a few days.
The programme stated that natural diamonds come from trees which have fallen and have been crushed by rocks for thousands of years. The artificial diamonds had to be cut and polished by craftsmen in the same way as natural diamonds and although they were yellow and much larger than usual as jewellery, they were very cheap comparatively.
2.Ceramic Knives.
These are stronger than stainless steel and never need to be resharpened.
In the process of manufacture some metal particles are introduced so that they will set off scanning alarms at airports.
They are very popular with chefs, apparently.
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What's new ? They hav been making diamonds for the past 30+ years .
The Russians were the first to make them . However it was found people still prefer to pay 50 times more for the real thing so it never became popular . In addition De Beers did/do everything to discredit their use.
As far as knives are concerned diamond saws and drills are made from all the diamond dust produced by the diamond industry relatvely cheaply so there is little point in producing it artificially .
The Russians were the first to make them . However it was found people still prefer to pay 50 times more for the real thing so it never became popular . In addition De Beers did/do everything to discredit their use.
As far as knives are concerned diamond saws and drills are made from all the diamond dust produced by the diamond industry relatvely cheaply so there is little point in producing it artificially .
I have no idea what you are trying to get at in point one. Manmade diamonds have been around for yonks.
With regards ceramic knives they are not that popular with chefs as they are expensive and, as has been said, very fragile. They are no good in a busy kitchen and no good in a domestic setting with stone floors or other hard surfaces. The only positive is that they do retain a good edge.
With regards ceramic knives they are not that popular with chefs as they are expensive and, as has been said, very fragile. They are no good in a busy kitchen and no good in a domestic setting with stone floors or other hard surfaces. The only positive is that they do retain a good edge.
Thank you for your corrections and comments heathfield, woofgang, modeller, Eccles Cake, and jomifl.
The film showed sushi chefs slicing fish with ceramic knives.They liked the knives because the stayed sharp.The film also stated that the knivers were virtually unbreakable and were second only to diamonds in terms of hardness.
The film showed that real diamonds are formed when a tree, for example, is burnt by a volcano and crushed beneath the earth's surface for several millions of years.
The film showed sushi chefs slicing fish with ceramic knives.They liked the knives because the stayed sharp.The film also stated that the knivers were virtually unbreakable and were second only to diamonds in terms of hardness.
The film showed that real diamonds are formed when a tree, for example, is burnt by a volcano and crushed beneath the earth's surface for several millions of years.
//The film showed that real diamonds are formed when a tree, for example, is burnt by a volcano and crushed beneath the earth's surface for several millions of years.//
Don't believe everything you see on television. They might well have claimed it but it is rubbish. One thing for certain they didn't observe it happening.
Here are the facts.
Carbon is soluble in iron. Indeed the chemistry of carbon and iron is fundamental to steel-making technologies. Iron carbide is a very hard material that makes some types of steel very hard and brittle.
The rate of cooling controls the size and types of carbide crystals that form in the steel. If the amount of carbon is just right (about 0.7 percent) and cooled at the right rate the steel can be both tough and hard.
Cool it too fast and the steel is hard but brittle. Cool it slowly and the steel is soft and ductile.
Put simply hardness is enhanced by "quenching" red hot steel in water or oil. Then the steel is "tempered" by reheating to reform the structure resulting in hard carbide crystals in a matrix of ductile iron. Getting the crystals the right size is the issue.
Too much carbon and it precipitates as graphite which is why cast iron is relatively soft.
If the carbon rich iron is cooled very very very slowly under intense pressure the carbon crystallises as diamond rather than being combined with iron as carbide.
The process is the same as forming crystals from any solution. Most science students experience the formation of a copper sulphate crystal from a saturated solution during science classes at school. The slower the cooling the bigger the crystal.
Same with carbon crystals from a saturated solution in molten iron. Slow cooling, big crystals.
Don't believe everything you see on television. They might well have claimed it but it is rubbish. One thing for certain they didn't observe it happening.
Here are the facts.
Carbon is soluble in iron. Indeed the chemistry of carbon and iron is fundamental to steel-making technologies. Iron carbide is a very hard material that makes some types of steel very hard and brittle.
The rate of cooling controls the size and types of carbide crystals that form in the steel. If the amount of carbon is just right (about 0.7 percent) and cooled at the right rate the steel can be both tough and hard.
Cool it too fast and the steel is hard but brittle. Cool it slowly and the steel is soft and ductile.
Put simply hardness is enhanced by "quenching" red hot steel in water or oil. Then the steel is "tempered" by reheating to reform the structure resulting in hard carbide crystals in a matrix of ductile iron. Getting the crystals the right size is the issue.
Too much carbon and it precipitates as graphite which is why cast iron is relatively soft.
If the carbon rich iron is cooled very very very slowly under intense pressure the carbon crystallises as diamond rather than being combined with iron as carbide.
The process is the same as forming crystals from any solution. Most science students experience the formation of a copper sulphate crystal from a saturated solution during science classes at school. The slower the cooling the bigger the crystal.
Same with carbon crystals from a saturated solution in molten iron. Slow cooling, big crystals.
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