Research on Processing Methods of Cast Superalloy Materials.（HY industry- Technical Center internal data）
-
Over the years, Shanghai HY has been committed to the research and testing of advanced processing methods for high-temperature alloy casting, Same like engine blade,dental materials,oil valve stem etc. Hoping to provide customers with super cost-effective castings.
-
In this paper, the material parameters and typical characteristics of the parts are studied in combination with the cutting parameters of the parts. The processing methods of the cast superalloy materials are discussed in depth. The fabrication of the material parts is realized by two methods, and the best method for processing the superalloy materials is obtained. Find a cutting method that improves the processing efficiency of cast superalloy materials and reduces manufacturing costs.
Research background and significance:
According to statistics, by 2008, cutting processing accounted for more than 85% of the machining volume. Therefore, improving the efficiency and quality of cutting and reducing the processing cost is an important issue in the mechanical manufacturing industry.
Cast superalloy material features:
-
high hardness;
-
high strength;
-
low thermal conductivity;
-
low plasticity and high brittleness;
-
microscopic hard spots or hard inclusions.
The cutting process of the material conforms to the general principles and laws of metal cutting, and also has its own distinctive features:
-
large cutting force, high cutting temperature
-
severe work hardening
-
strong chemical affinity, easy to produce sticky knife phenomenon
-
Friction of high hardness points
-
Chips are difficult to handle.
For example, K24 material is very difficult to machine. The processing breakthrough of this kind of material has far-reaching significance for deeper processing research, and the recommended coefficient of superalloy material is Km.
Past processing method：
-
For the conventional processing methods for Cast Superalloy, we rely on the accumulation of workers’ experience and use ordinary machine tools for machining. For the tool, some inserts (YD type) cemented carbide are used to obtain a set of suitable cutting parameters.
-
However, the requirements for tool design, selection, manufacturing and management of the main cutting tasks are getting higher and higher, the difficulty is getting bigger and bigger, the proportion of tool costs in production costs is also increasing, and the selection of cutting parameters during processing. And optimizing the impact on processing efficiency and quality is already critical.
solution：
Through the generation of the above problems and the analysis of the causes, several processing schemes have been developed. The effects of other methods are not very clear. such as: ordinary milling, by improving the cutting tools, etc., only the following two successful processing schemes are introduced here.
CNC machine tool high speed machining:
-
The CNC machine tool system has good rigidity. The hydraulic clamping workpiece is stronger than the ordinary machine tool. The selection of the tool is an important part of the CNC machining process. It not only affects the machining efficiency of the CNC machine tool, but also directly affects the processing quality. Currently on the market. Most of them use CVD coated carbide inserts.
-
In order to achieve higher wear resistance, the indexable inserts are multi-layer coated. Some machining requirements are very strict on the blade. The blade must have a sharp cutting edge to reduce the roughness of the finished surface, and it must have extremely high wear resistance to ensure the shape accuracy of the workpiece.
-
According to the test conclusion, the rotation speed is 80m/min; the feed rate is 1200mm/min; and the cutting depth is 0.1mm.
-
Considering the processing efficiency, tool cost and other factors, select a SS-ER4-PL tool from a tool factory, and process it under this processing parameter, and optimize the results.
Research on electrical processing methods:
Processing method of casting high-temperature alloy materials – electrical processing, including EDM machine and wire cutting machine processing.
The processing is a self-excited discharge, and its characteristics are as follows:
Between two electrodes of the spark discharge have a higher voltage before the discharge, and when the two electrodes are close, the spark discharge occurs immediately after the medium is broken down. With the breakdown process, the resistance between the two electrodes sharply decreases, and the voltage between the two poles also sharply decreases. The method of sizing materials by the corrosion phenomenon generated by spark discharge is not obvious because the electrical discharge machining varies from material to material.
Characteristics of Electrosurgical Application in Casting Superalloy Materials:
-
The energy density of pulse discharge is high, which is convenient for processing special materials and complex shapes of workpieces that are difficult to machine or cannot be processed by ordinary machining methods. Not affected by material hardness, not affected by heat treatment conditions.
-
the pulse discharge duration is extremely short, the heat conduction diffusion range generated during discharge is small, and the material is affected by heat.
-
during processing, the tool electrode is not in contact with the workpiece material, and the macroscopic force between the two is extremely small. The tool electrode material does not need to be harder than the workpiece material, so the tool electrode is easy to manufacture.
-
the structure of the workpiece can be reformed, the processing technology can be simplified, the service life of the workpiece can be improved, and the labor intensity of workers can be reduced.
Summary and prospect:
-
According to the practice, test and comparison of casting high-temperature alloy materials, the advantages of conventional machining, numerical control high-speed machining and electric machining are found. The cutting parameters of the tool, the cutting amount per tooth and the axial feed amount are related to various factors. In pursuit of the best cutting parameters, all factors must be considered.
-
Through this research, a variety of related factors such as machine tools and tools were solidified, and a set of effective parameters that can guide the actual processing of on-site parts was obtained. At present, the data obtained by the test is simulated on the spot.
-
With the continuous development of new materials and new process technologies, the future machining based on existing research will develop in the direction of high quality and high efficiency, and march into the field of integration.
-
Considering cutting should take all factors into consideration. It takes into account all the factors affecting the machining during the integration process, so that the cutting parameters are highly integrated.
-
In the near future, through our more efforts, the machining industry will continue to grow and develop, and cutting technology will catch up with international leading technologies.
