With the extensive development of mechanical manufacturing, there has been no significant breakthrough in part forming. It is primarily supported by several traditional methods. Even with the recent popularity of 3D printing, it is more likely to remain at the level of prototyping and impractical publicity. Sadly, it has not been widely and universally applied to the field of mechanical molding, which is a kind of sadness in the manufacturing industry.
Holding back has become an inevitable embarrassment.
Of course, many people are unfamiliar with traditional part forming methods, and most have little knowledge, including myself, as I only have a basic understanding of these methods.
Therefore, I will provide some basic information to give you a rudimentary understanding of part forming. Please feel free to point out any gaps or errors and offer additional information to improve this explanation, as I hope it will be informative.
Firstly, part forming is divided into two categories: material reduction forming, which involves removing material, and increasing material forming. Currently, material reduction forming remains the mainstream method of part forming.
01 Material reduction forming
There are many types of material reduction molding, which are primarily classified based on the type of part blanks used. Although the final method of material reduction still depends on the machining means, the source of the part’s blank can vary greatly. Therefore, the following classification is based solely on how the part’s blank is acquired.
A. profile reduction forming
As shown in the following figure:
Based on the image above, it is evident that many parts of our manufacturing process require blanks that result from the reduction processing of two types of profiles. The final shape and dimensional accuracy of the parts are achieved through various machining equipment, including wire cutting machines, lathes, milling machines, planers, boring machines, drilling machines, grinders, and others.
This molding method offers several advantages:
(1) Low processing cost: Since the materials used are standard, the purchasing cost can be effectively controlled.
(2) Short processing cycle: As the materials can be easily purchased from the material market, with most being readily available in stock.
(3) Good material quality: Standard profiles are more reliable in quality control, ensuring high-quality materials.
(4) Good processing adaptability: Most shapes can be processed with this molding method, as long as the high processing cost is not a deterrent.
This molding method is currently the most commonly used and is widely used by mechanical processing plants. Many such plants stock a certain base of raw materials to ensure optimal cost control and avoid periodic surpluses.
Furthermore, this molding method is the most frequently encountered mechanical processing method for mechanical engineering graduates. In fact, it could be a lifelong career in processing cycles, with the title of mechanical process engineer.
Although this method may seem straightforward, it requires a great deal of knowledge and expertise, which many people may never fully grasp.
B. casting molding reduction processing
As shown in the following figure:
From the picture above, it is apparent that the part’s blank originates from casting molding, but the casting parts must undergo further reduction to satisfy the product’s design requirements.
The processing means and methods are basically identical to those of the aforementioned profiles, with the casting parts having the following characteristics:
(1) They can be made into various special-shaped parts, and the margin for reducing materials during machining can be significantly reduced.
(2) The machining cost of parts can be minimized because the machining allowance can be controlled.
(3) The selection of materials for parts can be more flexible, and the product can have better adaptability.
(4) There are some hidden risks associated with material uniformity, and removing casting stress can be quite challenging. Some businesses may even cut corners in these areas.
(5) The cost of the part’s blank is too high, particularly for parts that cannot be manufactured in batches.
In reality, casting parts are a hazardous undertaking.
A friend of mine once worked for a relatively large foundry enterprise. One day, while the crane was transporting a bowl of molten iron to cast, the steel wire broke, causing the molten iron to spill instantly, melting the workers below to the point of no return.
My friend was so terrified that he resigned the next day, and it remains a traumatic experience that haunts him to this day.
Therefore, I seldom visit foundries. Even if my company arranges it, I try to avoid entering the dangerous area because I also have a phobia.
As the adage goes, a wise man never stands under a perilous wall, and I remind myself always to steer clear of danger.
However, this type of part forming is the prevalent method that cannot be avoided in the machinery industry, especially in the creation of large-scale equipment.
Perhaps advancements in automation technology can transform this traditional method of work, making it safer and more straightforward, but there is still a long way to go.
C. forging forming reduction processing
As shown in the following figure:
From the picture above, we can see that the parts are formed through forging, which is a very ancient part-forming process.
Ironworking is the most primitive form of forging, and it was once a dream of mine.
In fact, I have always had a fondness for traditional mechanical processing, and I believe it is a reflection of human technology.
Blacksmithing is a very talented profession. Wei Chi Gong, the founding general of the Tang Dynasty, was a blacksmith. Mo Ye, the maker of a famous sword in ancient times, was also a blacksmith, and the founder of the Longquan Sword, Mr. Ou Ye Zi, was also a blacksmith.
When one reaches a certain level as a blacksmith, they are not referred to as a blacksmith, but rather as a master, making it a very powerful technical profession.
In modern times, the forging process has begun to become automated.
About half a year ago, I visited a company and went to a forging workshop, which was beyond our understanding.
The workshop was very clean, so clean that it was not in line with the image of forging. All forging processes were performed through ABB manipulators. Processing data were also recorded and outputted as corresponding statistics, making it appear to be an intelligent factory.
The forging equipment left a profound impact on me. The director told us that the purchase price of the equipment was close to 100 million.
This is what it means to be a company with significant assets.
In front of this forging equipment, luxury cars and mansions were insignificant.
Forged parts possess the following characteristics:
(1) It can enhance the microstructure and mechanical properties of the parts.
Hot working deformation causes metal to realize recrystallization and changes the original coarse dendrites and columnar grains into equiaxed recrystallized structures with fine grains and uniform size. This compacts and welds the original material, resulting in the elimination of segregation, porosity, and slag inclusion. The microstructure becomes tighter, and the plasticity and mechanical properties of the metal are improved.
(2) Profiling forging can be performed according to the final shape required for the parts, reducing the machining allowance of the parts and saving processing costs.
However, from the picture above, we can still see that forging is a hazardous profession.
If it is performed entirely manually, its risk level is not inferior to that of casting molding. Therefore, an intelligent factory based on automation is the fundamental solution to this problem, and many enterprises now have excellent application cases.
We look forward to a brighter future.
These three part-forming methods are more typical and general methods of reducing material forming, and they are also the most common methods used in enterprises.
Basically, these three methods are the main methods we encounter in enterprises.
02 Increasing material forming
When it comes to molding, we must discuss 3D printing technology. This technology has gained immense popularity, especially in news media. Many 3D printed products have subverted our perception of what’s possible, including 3D printed cars, 3D printed pistols, and other products.
While there is a tendency to replace traditional reduced material forming techniques with 3D printing, this is still a long way off. Currently, there is little possibility that this technology can completely replace traditional molding methods. Perhaps it’s merely a good storytelling gimmick that many people use to sell the future and dreams.
To learn more about the 3D printing process, please refer to the following set of pictures.
My understanding of 3D printing is limited to making the first edition of a sample. When developing products, 3D printing products are often used, but the printing effect is often unsatisfactory. The surface roughness may be poor, or the printed parts may be incomplete.
In short, my experience has been limited to the printing of plastic parts, and I may be ill-informed about this technology. It’s possible that I am not very optimistic about 3D printing because I have not had the opportunity to come into contact with high-end 3D printing products.
However, despite its imperfections, 3D printing is undoubtedly a part forming method with great potential for the future. Therefore, we should be optimistic about understanding it.
In summary, my assessment is based on my personal knowledge and experience with some parts forming methods. If you have a better way to share, let’s share it, and together, we can make the world a better place.