Materials science

Review questions:
1. How are brasses, bronzes, aluminum alloys alloys marked?
2. Describe the specific features in the structure of alloys of non-ferrous metals.
3. How do the structures and properties of aluminum alloys change as a result of heat treatment?
4. What are the properties and structure of B 83 babbitt?

10 – LABORATORY WORK


General structure of milling machines.

1. Purpose of work.

Studying the structure and operation of the 7Ye35 cross-cutting machine, adjusting the machine to work.

2. Necessary equipment and tools.

2.1. 7Ye35 model cross-boring lathe.

2.2. Slotting cutter.
2.3. Workable zagotovka.
2.4. Zagotovka locking pin.
2.5. Barbell circular.

3. General concepts of processing on cross-cutting machines.

Cross-grooving machines are designed for the processing of short zagotovka by grooving. These machines are used for processing planes, opening various grooves and processing linear surfaces.

The peculiarity of cross-cutting machines is that they have a cutting movement along a straight line (reciprocating).
Various operations are performed on cross-cutting machines. Horizontal, vertical and inclined surfaces are scored by pushing in the desired direction with the help of passing or moving cutters. Cutting and trenching works are performed with cutting chisels. When the depth of the groove is large, its width is smaller than the width of the groove so that the cutter does not break, and the cutting is done step by step. Grooves in the form of tavr and kaldir open tails are carved with chisels of appropriate configuration. On one side, the cutting edge is not thrown away when going back. Shaped linear surfaces are treated with shaped chisels, or with planar chisels .

4. Cross - the structure of the milling machine.

In cross-cutting machines, the cutting movement is performed by a cutter attached to the support of the machine belt. When working on a horizontal surface, the pushing movement is given to the table on which the cutting tool is installed, when working on a vertical or inclined surface, the cutter is installed and the support is pushed.

The general view of the 7Ye35 model cross-boring lathe is shown in Figure 1. The frame 2, in which the cutting movement is installed , has horizontal and vertical guides. Support 8 is installed on the front part of the strap.
The table 6 is pushed along the guides of the traverse 3 along with the processed zagotovka installed on it, and the base plate 1 is held by the rack 5 installed on it.

Figure 1. General view of the 7Ye35 cross-cutting machine.

V _px - working walking speed; V _xx – walking speed; S _n – transverse thrust; С _v – vertical push; S _y is installation displacement. 1 – base plate; 2 – staina; 3 – traverse; 4 – telescopic screw; 5 – stand; 6 – table; 7 – sharp blade; 8 – support; 9 – polzun.

5. Principles of adjusting the machine tool for planing.

The zagotovka to be processed is attached to the frame of the machine. Depending on the size of the zagotovka, it should be installed at the required height.

The cutter is selected and attached to the cutter probe of the support.
With support, the wrist is moved back and forth. During its forward movement, the zagotovka is released from the zagotovka (working path), and when it moves backwards (salt walk) - the dross is not released.
The periodic push is done by pushing the table at the end of the slide's stroke.
The desired walking path of the belt is made by adjusting the belt.
6. Procedure for performing the work.

6.1. Getting to know the structure and operation of the 7Ye35 model machine.

6.2. Installing and fixing the cutter on the machine.
6.3. Installation and fixing of the workpiece to be processed on the table of the machine using a device.
6.4. Adjustment of the number of table moves and the number of double walks of the slider to the required amount with the help of a leader or master (table 1).
6.5. Processing of zagotovka.
6.6. Taking out the processed zagotovka from the table and determining its dimensions with the help of a tool.
6.7. Remove the setting.

7. Transverse - options for adjusting the milling machine.

Options	1	2	3	4	5	6	7	8	9	10
Processing length, mm	100	300	350	150	450	400	170	220	90	80
Cutting speed m/min	30	35	40	45	20	25	27	27	18	15
Table displacement, mm/couple of steps.	0.20	0.22	0.30	0.35	0.18	0.19	0.21	0.15	0.15	0.10

Note: Zagotovka material is steel 30.