What effect does special processing have on the machinability of materials and the manufacturability of structures?

What effect does special processing have on the machinability of materials and the manufacturability of structures? 1. improves the machinability of the material. Diamond, cemented carbide, hardened steel, aging, glass and ceramics are usually difficult to machine. EDM, electrolysis, laser and other machining methods make tools, tools and drawing dies made of diamond and polycrystalline (synthetic) diamond widely used, and the machinability of materials is no longer directly related to hardness, strength, toughness and brittleness. For example, for WEDM, hardened steel is easier to machine than unhardened steel. Special processing technology makes the machinable range of materials develop from ordinary materials to hard gold, superhard materials and special materials. 2. The typical process route of parts has changed. In traditional machining (except grinding), cutting and forming must be arranged before quenching, which is a technical criterion that all technicians must abide by, but the appearance of special machining has changed this unchangeable format. Because the special machining is basically not affected by the hardness of the workpiece, in order to avoid the deformation caused by quenching after machining, the machining is generally carried out after quenching. The most typical machining methods are WEDM, EDM and ECM.

The appearance of special treatment also affected the "dispersion" and "concentration" of previous processes. Because there is no obvious mechanical force in the process of special machining, the strength and stiffness of machine tools, fixtures and cutters are not the main problems, so even large and complex machined surfaces can be machined with a complex cutter after one clamping and one working procedure, and the working procedures are relatively concentrated.

3. Shorten the trial production cycle of new products. During the trial production of new products, all kinds of standard and nonstandard spur gears, silicon steel sheets of micromotor rotors, all kinds of transformer cores, all kinds of complex and special quadric surfaces and other parts can be directly processed by special processing technology, which saves the design and manufacture of corresponding fixtures, fixtures, measuring tools, molds and secondary fixtures, and greatly shortens the trial production cycle. Rapid prototyping technology is a necessary means of trial production of new products, which has changed the traditional trial production mode in the past.

4. The structural design of product parts has great influence. In the past, it was difficult to manufacture all kinds of complicated molds, which were generally made into mosaic structures. After using WEDM technology, even cemented carbide dies or tools can be made into an integral structure. Due to the appearance of electrochemical machining, the turbine of jet engine can also adopt the integral structure with crown, which greatly improves the efficiency of the engine.

5. The standard for measuring the manufacturability of traditional structures has been changed. Square holes, small holes, deep holes, curved holes and narrow slits are considered as typical examples of poor manufacturability, which are very taboo for process designers and even considered as forbidden areas for mechanical structures. But for EDM piercing and EDM cutting workers, the difficulty of square hole and round hole is the same. After using EDM technology, the manufacturability of spinneret holes, spinneret holes, a large number of small cooling deep holes and narrow grooves on the oil pocket inside the turbine blade, hydrostatic bearing and hydrostatic guide rail has been improved. When the traditional machining method is adopted, if the work of drilling locating pins and milling grooves is omitted before quenching treatment, the workpiece can only be scrapped after quenching treatment, and now it can be remedied by electric spark drilling and grooving. Moreover, in order to avoid defects such as cracking and deformation caused by quenching treatment, drilling, slotting and other processes are specially arranged after quenching treatment, which makes the arrangement of process routes more flexible.

Special processing technology has become the key technology and cutting-edge technology to win in international competition. The development of modern industries such as national defense industry and microelectronics industry requires the use of special processing technology to manufacture related instruments, devices and products. China's special processing technology not only has broad social needs, but also has great development potential. At present, there is still a big gap between China's overall technical level of special processing and that of developed countries, which requires us to constantly struggle and work hard to speed up related work and promote the research and development, popularization and application of special processing technology in China.

What are the factors that affect the machinability of NdFeB? There are many factors that affect coercivity, such as formula, melting, milling and sintering (tempering).

Is lightweight brick machinable? Dongfeng Heavy Industry Machinery Factory has various specifications and sizes, and has good processability. Non-steaming aerated block (brick) has various specifications and sizes, which can meet various masonry needs. Coarse aggregate is not used in production, but can be sawed, planed, glued and nailed, and processed as needed, which is convenient for decoration.

How does process efficiency affect the manufacturing and processing of parts? The structural manufacturability of parts refers to the feasibility and economy of manufacturing design parts on the premise of meeting the use requirements. The following will analyze the structural manufacturability of parts from two aspects: machining and assembly.

(A) mechanical processing requirements of parts structure

1. The structure of parts that are convenient for clamping should be convenient for positioning and clamping during machining, and the clamping times should be less. The parts shown in fig. 3-10a are intended to be clamped by a tip and a heart-shaped chuck, but this structure is not convenient for clamping. If the structure shown in Figure B is changed, the chuck can be installed conveniently.

2. For parts that are easy to process, standardized values should be used as much as possible, so as to use standardized tools and measuring tools. At the same time, we should also pay attention to the withdrawal and feed of the tool, so that it is easy to ensure the machining accuracy requirements and reduce the machining area and difficult-to-machine surfaces. Table 3-8b gives an example of the structure of parts that are convenient for machining.

3. It is convenient for NC machine tool processing.

The NC manufacturability of machined parts involves a wide range. The following is a manufacturability analysis based on the possibility and convenience of programming.

The convenience of programming is often an index to measure the manufacturability of NC. For example, as shown in Figure 3- 1 1, a part has undergone an abstract dimensioning method. If the source program of the part is written in APT language, it will be difficult to describe the shape of the part with geometric definition statements, because point B and its straight line OB are difficult to define. To solve this problem, we need to make a detour, that is, first make a straight line L 3 parallel to L 1 through point B and define it, then define straight line AB, so as to find the intersection point B between L 3 and straight line AB, and then define OB. Otherwise, manual calculation outside the machine should be carried out to avoid it as much as possible. It can be seen that the dimensioning method on the part drawing has great influence on the manufacturability. Therefore, different requirements should be put forward for the design drawings of parts, and the dimensional data given on the drawings should conform to the principle that all parts are easy to program in NC machining.

It is best to adopt uniform geometric type or size for the shape and cavity of parts, so as to reduce the number of tool changes, and control programs or special programs can also be used to shorten the program length. Because the fillet size determines the tool diameter, it is easy to see whether the manufacturability is good or bad. Therefore, for some main NC machining parts, it is suggested to adopt standardized design structure and size. It shows that the machining of ball-end milling cutter should be avoided as far as possible (R=r at this time), and generally considered as d=2(R-r). In addition, some CNC machine tools have the function of symmetrical machining. For some symmetrical parts, as shown in Figure 3- 13, only half programming is needed, which can save a lot of programming time.

4. Easy to measure

When designing the structure of parts, the possibility and convenience of measurement should also be considered. It is required to measure the parallelism between the center line of the hole and the reference plane A. Because the bottom boss is biased to one side, it is difficult to measure the parallelism. A symmetrical process boss is added in the middle, and the position of the boss is in the middle, so the measurement is greatly convenient at this time.

Aerated concrete has machinability. Aerated concrete is a new type of building material, which is light, porous, heat-insulating, fireproof, nailing, sawing and planing, and has certain seismic performance.

1. Lightweight

2. Good heat preservation effect.

3. High strength

4. Good seismic performance

5. Good processing efficiency

6. It has certain high temperature resistance.

7. Good sound insulation effect

8. It is conducive to mechanized construction.

9. Strong adaptability

What are the effects of special processing on mechanical manufacturing technology? 1, change the typical process route of parts.

2. Shorten the trial period of new products.

3. It affects the structural design of product parts.

4. Re-measure the manufacturability of traditional structures.

Whether No.6 stellite-based covered electrode can be machined or not, the hardness index after welding is generally 3~5 degrees lower than that in written materials, and the specific degree is also related to welding technology.

What is the effect of surface machining and non-machining on high frequency quenching? The product is quenched by high frequency after quenching and tempering, and the material is 45 steel. The current technology is rough turning, tempering, semi-finish turning and high frequency. I want to change the process to rough turning, tempering and high frequency.

What effect does hardenability have on heat treatment process and material selection? Heat treatment process: it has influence on the selection of quenching medium. Oil cooling or even air cooling can be selected for those with high hardenability, and quenching medium with fast cooling speed can be selected for those with low hardenability.

Material selection: the whole section of the part is uniformly stressed and the stress state is complex, so the steel with high hardenability should be selected.

Heat treatment refers to the metal hot working process in which materials are heated, insulated and cooled in solid state to obtain the expected structure and efficiency.

Hardenability: the ability of steel to obtain the depth of hardened layer when quenching. Depth of hardened layer, also called depth of hardened layer; It refers to the depth from the surface of steel to the semi-martensitic region of steel (martensite accounts for 50%, and the other 50% is pearlescent structure) (there are also some steels such as tool steel and bearing steel that need to be measured to 90% or 95% martensite region). The deeper the hardened layer of steel, the better the hardenability of the steel.

How does the carbon content of mechanical engineering materials affect the mechanical efficiency and process efficiency of steel materials? The general law of the influence of carbon content of steel on mechanical efficiency is: the higher the carbon content, the higher the strength and hardness of steel, while the plasticity and toughness will decrease; On the contrary, the lower the carbon content, the lower the strength and hardness of steel, but the higher the plasticity and toughness.

The influence of carbon content of steel on process efficiency is that with the increase of carbon content, the machinability and weldability of steel become worse, and the hardening ability of heat treatment increases, and vice versa.