Metallographic sample preparation is a technical job, and cutting is the first. The quality of cutting directly determines whether the entire sample preparation process can be successful, so it is very critical. The sample maker needs to understand the basic conditions of the target material, such as the mechanical performance indicators such as hardness and strength of the material, the key observation points, and the taboo requirements of the target material. Then, according to these characteristics, the appropriate cutting process can be formulated.

Cutting is to cut the original sample to obtain the most representative target analysis surface. And cutting is essentially the process of removing the slit material. The cutting disc rotates at high speed to make the hard abrasive particles protruding on the surface impact the sample, and the sample is cut by self-loss.

The cutting process is completed by the cutting machine. A stable, reliable and powerful cutting machine is a necessary prerequisite for the cutting process. However, there are many types of cutting machines on the market, and the quality is uneven. How to choose a suitable cutting machine? The editor believes that it should be evaluated from the following dimensions:

1. Meet specific functional requirements:

For single conventional material analysis, an ordinary desktop manual cutting machine is OK; for material analysis of multiple conventional sizes, a fully automatic manual-automatic cutting machine can be selected; if it is sampling and secondary cutting on large parts, a large cutting machine is required; if precise positioning cutting is required, a precision cutting machine can be selected.

2. Corrosion resistance treatment:

In most cutting conditions, cutting coolant is introduced, so the corrosion resistance level of the entire cabin is very high. The base and workbench are preferably made of aluminum or stainless steel, but this material is expensive, so many manufacturers use nickel plating and chrome plating on steel parts. Rust will appear as the plating wears out; some even paint directly on the steel parts, and cracks or slight defects on the paint surface will cause large-scale peeling and rust. Plastic materials are best used for covering parts, which are light and durable.

3. Stable structure and good rigidity:

To evaluate the rigidity of the cutting machine, the simple and crude way is to look at the weight, because the weight generally comes from the base and the workbench. If the material is sufficient, then the weight is not a problem. The low center of gravity will cause less vibration during cutting, so the cutting surface will naturally be smoother. In addition, generally speaking, the integrated structure is better than the spliced structure.

4. Good flexibility of the workbench:

The workbench is one of the core parts of the cutting machine. It is the actuator for clamping samples and cutting and walking, and is also the basic platform for expanding various fixtures. The entry-level cutting machine workbench is fixed and cuts samples according to the downward trajectory of the cutting blade. The automatic cutting machine requires the workbench to realize programmable movement in the Y direction. In addition to realizing programmable movement in the Y direction, the top-end cutting machine workbench also supports programmable movement in the X direction of some areas, so that automatic batch cutting can be realized.

5. Speed adaptive function:

Usually, the breakage of the cutting blade is caused by cutting overload. High-end cutting machines should have the function of automatic detection of the cutting blade speed. When the resistance is too large and the speed drops, the Y-axis feeding will be automatically delayed or stopped, and the feeding will be resumed after the cutting blade speed is fully restored. This can prevent the saw blade from breaking due to overload and protect the sample from overheating and burning.

6. Complete fixtures:

The fixture is critical to the cutting effect. When purchasing equipment, you must be clear about the type and number of fixtures. A good fixture combination will make cutting more efficient.

7. Human-machine interface:

Due to the complex parameters, a simple and easy-to-understand human-machine interface will make it easy for users to control.

8. High-end components:

Since the cutting machine is a high-speed device and works in a corrosive environment, it has high requirements for the durability of various components. Many bad manufacturers use unbranded components. There are no problems in the early stage of use, but many problems occur after the warranty period, which greatly affects the utilization efficiency of the equipment. Therefore, do not blindly pursue cheapness when purchasing.

In short, if you want to do your job well, you must first sharpen your tools. Reliable and powerful cutting equipment is the basic prerequisite for cutting; a variety of clamping tools, cutting disc types and cutting coolant varieties are important guarantees for cutting; finally, combined with skilled experience and skills, you can get the ideal cutting sample.

If you have any troubles in metallographic sample preparation, you may wish to consult the professional metallographic technicians of Shanghai Truer Company, or entrust them to prepare samples. Truer Company has more than ten years of experience in complete analysis and has handled thousands of difficult cases. I believe it will be helpful to you.

As a professional metallographic solution provider in China, Shanghai Truer Industrial Development Co., Ltd. takes international giants as benchmarks, faces difficulties, concentrates on research, overcomes key equipment and consumables that restrict the development of the industry, and creates a complete metallographic industry chain integrating equipment, consumables and sample preparation training; the company is equipped with a cutting-edge metallographic laboratory and has a high-quality team of experts. For more than ten years, it has provided metallographic analysis and sample preparation training services to thousands of customers, and provides customized metallographic laboratory solutions.