A kind of processing method of noble metal commemorative coin
Technical field
The invention belongs to noble metal to shape technical field, more particularly to a kind of processing side of noble metal commemorative coin
Method.
Background technology
Noble metal is typically conventional to be had:Au Ag Pt Pd and its alloy, manufacture ornaments and industrial components it is general use with
Lower process manufacture:Make by hand, hot investment casting, pressure processing, machining, electroforming, the methods of welding.In noble metal pearl
In class ornament, the pearl class and chain class noble metal jewelry of various styles and moulding so that the species of precious metal jewelry is complicated, but
Therefore the technological ability and technical merit of manufacturing enterprise are challenged, therefore, noble metal jewelry processing factory is generally provided with stock portion,
With realize noble metal ingot is stretched in various plant equipment, punching press, winding, the operation such as shearing, be entering for other departments
The processing of one step prepares preliminary blank, therefore, the plant equipment developed in noble metal processing have arm-tie, drawing machine, tablet press machine,
Oil pressure die press, eat up part of die press, twisted piece machine etc..
At present, existing noble metal commemorative coin is also more important there is one in quality the problem of, i.e. commemorative coin corrosion resistant
The problem of losing and be wear-resisting.In the collection of noble metal commemorative coin, commemorative coin is often corroded and aoxidized by external environment condition, such as
People when collecting gold commemorative coin, gold commemorative coin with application on human skin contact after, can absorb application on human skin toxin and sweat and send out
Dark hair is yellow, meanwhile, gold commemorative coin can also be with the daily necessities of people(Such as the mercury in cosmetics)Occur with the sulphur in air anti-
Should and black, can also be because on the surface of gold commemorative coin when gold commemorative coin is with platinum ring or platinum necklace phase mutual friction
Rub platinum and turn white, these problems can all damage the interests of collector;Due to purity higher gold and silver, their softness
Degree is higher, and wearability is lower, when people are collecting gold and silver coin, in long-term scratch, and the quality of gold and silver
It can slowly reduce, influence the weight and dimensional accuracy of commemorative coin, these problems can all cause the reduction of the reserve value of commemorative coin.
The content of the invention
The goal of the invention of the present invention is:For above-mentioned problem, there is provided a kind of processing side of noble metal commemorative coin
Method, by optimizing rolling mill practice, noble metal commemorative coin is produced with the mode that Sheet Metal Forming Technology is combined using technology for plating titanium, is being protected
In the case of demonstrate,proving Forming Quality and machining accuracy, wearability, corrosion resistance and the hardness of noble metal commemorative coin are improved, makes noble metal
Commemorative coin is guaranteed the quality for a long time.
To reach above-mentioned purpose, the technical solution adopted by the present invention is as follows:A kind of processing method of noble metal commemorative coin, bag
Include following steps:
Step 1: according to the product design figure of the noble metal of required processing, the diel of press is made;
Step 2: the blank of noble metal is pressed into the lath for meeting design requirement by roll squeezer;
Step 3: after the completion of step 2, by magnetron sputtering method on the surface of noble metal lath, last layer titanium film is plated;
Step 4: the lath obtained in step 3 is made annealing treatment, breaking down, breaking down then are carried out to noble metal blank
After obtain noble metal blank, noble metal blank is made annealing treatment, finish rolling is carried out after annealing, after the completion of finish rolling, to noble metal
Blank is punched, and obtains the semi-finished product base cake for meeting design shape, size and performance;
Step 5: obtained base cake is carried out into surface clean, it is then placed in the keg of centrifugal finishing machine, starts motor,
The major parameter of centrifugal finishing machine is adjusted, the rotating speed of centrifugal finishing machine is carried out light decorations process, light decorations for 300-500rad/min
After having handled, place into and 3-5h is soaked in absolute ethyl alcohol, finally take out drying, obtain finished product base cake;
Step 6: obtained finished product base cake is suppressed with the press of the diel designed and produced, obtain required
The commemorative coin of surface configuration.
In above-mentioned processing step, the surface plating last layer titanium film of noble metal lath, noble metal lath can be prevented in heat
Oxide layer is formed during processing, reduces the processing loss of noble metal, if noble metal lath is undersized, the side of titanizing can be passed through
Formula come meet design dimension precision requirement.After noble metal lath titanizing, semi-finished product base cake is obtained by rolling punching, due to titanium
Film has good plasticity, and in the process, in the operation of rolling extruding and extensional can occur for titanium film, can make titanium film by table
Face coating forms one layer of titanium-noble metal transition zone to noble metal internal penetration on precious metal surface, reaches similar and " oozes
The effect of titanium ", in heat treatment, the formation of this transition zone can be accelerated.On the one hand the transition zone of formation can make titanium film combine jail
Gu phenomena such as decortication hardly occurs, peels off, on the other hand, the compound that titanium is formed in noble metal can greatly improve expensive
Wearability, hardness and the resistance to Cavitation of metal surface, it is this although this effect is not as oozing effect caused by titanium technique
Mode is also sufficient for current demand compared with the performance for oozing the precious metal surface that titanium process costs are much lower, obtain.
In the noble metal commemorative coin finally given, due to titanium film have high rigidity, it is antifriction, do not peel off, be not easy to scratch
The features such as, it will not peel under ultraviolet light, these performances make noble metal commemorative coin not to be worn in scratch friction process, expensive
The weight of metal commemorative coin can almost keep constant weight;In corrosion resistance, titanium film has height anti-corrosive properties, and Surface of Titanium Film is either
Titanium nitride, titanium carbide or titanium carbonitride, all there is very strong chemical stability, not with general acid-base reaction, be not easy electrochemical
Corrosion is learned, will not can be protected the surface of noble metal commemorative coin with the chemical industry element reaction of mercury etc, precious metal surface is not sent out
The white phenomenon of hair tonic dark hair, will not also adhere to other metal ingredients;In durability, the color of the titanium film of formation is in long-term use
When will not also fade, anti-destructive is stronger, surface easy cleaning, after being adornd by light, the coupler surface of titanium film can keep it is long-term not
Become, noble metal commemorative coin is guaranteed the quality for a long time.
Further, the thickness of the titanium film in step 3 is 60-100 μm, to ensure the titanium layer to be meeted the requirements.
Further, to ensure machining accuracy and obtaining that thickness is uniform, the smooth noble metal blank of surfacing, in step 3
Finish-rolling process in, finally the draught pressure of finishing pass three times it is constant or reduce.
Further, in step 4, to the carry out size detection examination of obtained semi-finished product base cake, for undersize
Semi-finished product base cake, supplies size by way of titanizing, reduces the generation of percent defective.
In summary, by adopting the above-described technical solution, the beneficial effects of the invention are as follows:The noble metal souvenir of the present invention
The processing method of coin, by optimizing rolling mill practice, noble metal is produced with the mode that Sheet Metal Forming Technology is combined using technology for plating titanium
Commemorative coin, in the case where ensureing Forming Quality and machining accuracy, improve the wearability of noble metal commemorative coin, corrosion resistance and
Hardness, noble metal commemorative coin is set to guarantee the quality for a long time.
Embodiment
With reference to embodiment, the present invention is described in detail.
In order to make the purpose , technical scheme and advantage of the present invention be clearer, with reference to embodiments, to the present invention
It is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, it is not used to
Limit the present invention.
A kind of processing method of noble metal commemorative coin, comprises the following steps:
Step 1: according to the product design figure of the noble metal of required processing, the diel of press is made;
Step 2: the blank of noble metal is pressed into the lath for meeting design requirement by roll squeezer;
Step 3: after the completion of step 2, by magnetron sputtering method on the surface of noble metal lath, last layer titanium film is plated,
The thickness of titanium film is 60-100 μm(Specific thickness determines according to the species of noble metal and the specification of commemorative coin);
Step 4: the lath obtained in step 3 is made annealing treatment, breaking down, breaking down then are carried out to noble metal blank
After obtain noble metal blank, noble metal blank is made annealing treatment, finish rolling is carried out after annealing, wherein, finally finish rolling three times
The draught pressure of passage is constant or reduces;After the completion of finish rolling, noble metal blank is punched, obtain meeting design shape,
The semi-finished product base cake of size and performance, then again to the carry out size detection examination of obtained semi-finished product base cake, for size not
The semi-finished product base cake of foot, supplies size, to reduce the generation of percent defective by way of titanizing;
Step 5: obtained base cake is carried out into surface clean, it is then placed in the keg of centrifugal finishing machine, starts motor,
The major parameter of centrifugal finishing machine is adjusted, the rotating speed of centrifugal finishing machine is carried out light decorations process, light decorations for 300-500rad/min
After having handled, place into and 3-5h is soaked in absolute ethyl alcohol, finally take out drying, obtain finished product base cake;
Step 6: obtained finished product base cake is suppressed with the press of the diel designed and produced, obtain required
The commemorative coin of surface configuration.
The processing method of the noble metal commemorative coin of the present invention, by optimizing rolling mill practice, utilizes technology for plating titanium and presser
The mode that skill is combined produces noble metal commemorative coin, in the case where ensureing Forming Quality and machining accuracy, improves your gold
Belong to wearability, corrosion resistance and the hardness of commemorative coin, noble metal commemorative coin is guaranteed the quality for a long time.
The noble metal commemorative coin obtained by above-mentioned processing method, its wearability, corrosion resistance and hardness greatly improve, expensive
Metal commemorative coin can guarantee the quality for a long time, meanwhile,, can be according to your gold because titanium film has a variety of different colors in presentation quality
The color for belonging to commemorative coin selects paired color, and then after light decorations process, the smooth hardness in commemorative coin surface is high, and color is several
It is unchanged, the aesthetic value of commemorative coin is not influenceed.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all essences in the present invention
All any modification, equivalent and improvement made within refreshing and principle etc., should be included in the scope of the protection.