低溫脆性沖擊試驗(yàn)機(jī)

型號(hào)：BWD-C

國(guó)產(chǎn)低溫脆性試驗(yàn)儀廠家  結(jié)構(gòu)原理

A、本設(shè)備由制冷壓縮機(jī)主機(jī)體、加熱裝置、電子控制箱、冷卻槽、冷卻介質(zhì)循環(huán)系統(tǒng)、自動(dòng)報(bào)警裝置等部分組成。啟動(dòng)制冷開(kāi)關(guān)后，壓縮機(jī)開(kāi)始工作，制冷系統(tǒng)進(jìn)入正式工作狀態(tài)。制冷壓縮機(jī)連續(xù)不斷的工作，當(dāng)接近設(shè)定溫度時(shí)，冷卻槽中的加熱裝置開(kāi)始按比例提供熱量，用以平衡制冷系統(tǒng)產(chǎn)生的多余冷量，以達(dá)到恒溫的目的。攪拌可使冷卻槽內(nèi)的冷卻介質(zhì)不斷循環(huán)，使溫度均勻一致。

B、試樣夾持器

試樣一邊夾持4個(gè)試樣（橡膠類），另一邊夾持15個(gè)試樣（塑料類）。

C、沖擊裝置

沖擊裝置由沖擊錘和自鎖機(jī)構(gòu)組成。

D、沖擊器

沖擊頭半徑為1.6?0.1mm；

沖擊時(shí)，沖擊頭和試樣夾持器之間間隙為6.4?0.3mm；

沖擊頭的中心線與試樣夾持器之間的距離為8?0.3mm。

國(guó)產(chǎn)低溫脆性試驗(yàn)儀廠家  使用方法 

1接通電源，溫控儀和計(jì)時(shí)器顯示燈亮。 

2向冷井中注入冷凍介質(zhì)（一般為工業(yè)乙醇），其注入量應(yīng)保證夾持器的下端到液面的距離為75?10mm。 

3將試樣垂直夾在夾持器上。夾的不宜過(guò)緊或過(guò)松，以防止試樣變形或脫落。 

4按下夾持器，開(kāi)始冷凍試樣，同時(shí)啟動(dòng)時(shí)序控制開(kāi)關(guān)（或按動(dòng)秒表）計(jì)時(shí)。試樣冷凍時(shí)間規(guī)定為3.0?0.5min。試樣冷凍期間，冷凍介質(zhì)溫度波動(dòng)不得超過(guò)?1℃。 

5提起升降夾持器，使沖擊器在半秒鐘內(nèi)沖擊試樣。 

6取下試樣，將試樣按沖擊方向彎曲成180?，仔細(xì)觀察有無(wú)破壞。 

7試樣經(jīng)沖擊后（每個(gè)試樣只準(zhǔn)沖擊一次），如出現(xiàn)破壞時(shí)，應(yīng)提高冷凍介質(zhì)的溫度，否則降低其溫度，繼續(xù)進(jìn)行試驗(yàn)。 溫度，如這兩個(gè)結(jié)果相差不大于1℃時(shí)，即試驗(yàn)結(jié)束。 

技術(shù)參數(shù):

1.控溫范圍：室溫-70℃（室溫≤25℃）

2.恒溫精度：?0.3℃       

3.降溫速度：0℃～﹣30℃    約2.5℃/min

﹣30℃～﹣40℃   約2.5℃/min

﹣40℃～﹣70℃   約2.0℃/min

4.最大外形尺寸：900?500?800mm（長(zhǎng)?寬?高）

5.工作室有效工作空間：280?170?120mm（長(zhǎng)?寬?高）    

6.可裝試樣數(shù)量：1

7.數(shù)字計(jì)時(shí)器數(shù)字計(jì)時(shí)器：0秒-99分鐘，分辨率1秒

8.冷卻介質(zhì)：乙醇或其他不凍液

9.攪拌電機(jī)：8W

10.工作電源：220V--240V，50Hz，1.5kW

11.工作溫度:≤25℃

 Low temperature brittle impact testing machine
Model: BWD-C
Structural Principles
A、 This equipment consists of a refrigeration compressor main body, heating device, electronic control box, cooling tank, cooling medium circulation system, automatic alarm device, and other parts. After activating the refrigeration switch, the compressor starts working and the refrigeration system enters the official working state. The refrigeration compressor works continuously, and when it approaches the set temperature, the heating device in the cooling tank begins to provide heat proportionally to balance the excess cooling generated by the refrigeration system, in order to achieve constant temperature. Stirring can continuously circulate the cooling medium in the cooling tank, making the temperature uniform and consistent.
B、 Sample holder
Clamp 4 rubber samples on one side and 15 plastic samples on the other side.
C、 Impact device
The impact device consists of an impact hammer and a self-locking mechanism.
D、 Impactor
The radius of the impact head is 1.6 ? 0.1mm;
During impact, the gap between the impact head and the sample holder is 6.4 ? 0.3mm;
The distance between the centerline of the impact head and the specimen holder is 8 ? 0.3mm.
Usage method
1. Connect the power supply, and the temperature controller and timer display lights will turn on.  
Inject freezing medium (usually industrial ethanol) into the cold well in two directions, and the injection amount should ensure that the distance from the lower end of the clamp to the liquid level is 75 ? 10mm.  
3. Vertically clamp the sample onto the gripper. The clamp should not be too tight or too loose to prevent deformation or detachment of the sample.  
Press the gripper to start freezing the sample, and at the same time, activate the timing control switch (or press the stopwatch) to start timing. The freezing time for the sample is specified as 3.0 ? 0.5min. During the freezing period of the sample, the temperature fluctuation of the freezing medium shall not exceed ? 1 ℃.  
Lift the lifting gripper and allow the impactor to impact the specimen within half a second.  
Remove the sample and bend it 180 ? in the direction of impact, carefully observing for any damage.  
After the impact of 7 samples (each sample is only allowed to be impacted once), if damage occurs, the temperature of the freezing medium should be increased. Otherwise, the temperature should be lowered and the test should continue. When the temperature difference between these two results is no more than 1 ℃, the experiment ends.  
Technical parameters:
1. Temperature control range: room temperature -70 ℃ (room temperature ≤ 25 ℃)
2. Constant temperature accuracy: ? 0.3 ℃
3. Cooling rate: 0 ℃ to -30 ℃, approximately 2.5 ℃/min
-30 ℃ to -40 ℃, approximately 2.5 ℃/min
-40 ℃ to -70 ℃, approximately 2.0 ℃/min
4. Maximum external dimensions: 900 ? 500 ? 800mm (length ? width ? height)
5. Effective workspace in the studio: 280 x 170 x 120mm (length x width x height)
6. Number of samples that can be loaded: 1
7. Digital timer: 0 seconds to 99 minutes, resolution of 1 second
8. Cooling medium: ethanol or other non freezing liquid
9. Mixing motor: 8W
10. Working power supply: 220V -240V, 50Hz, 1.5kW
11. Working temperature: ≤ 25 ℃

傳熱介質(zhì)

在試驗(yàn)溫度下，能保持流動(dòng)，對(duì)試樣無(wú)附加影響的液體均可作傳熱介質(zhì)。這類傳熱介質(zhì)通常使用乙醇，此外還有丙酮、硅氧烷等。

試驗(yàn)報(bào)告

A本標(biāo)準(zhǔn)名稱或編號(hào)

B樣品的詳細(xì)說(shuō)明及其來(lái)源

C使用的傳熱介質(zhì)、致冷劑或其他降溫方式

D程序A:脆性溫度和試樣破壞現(xiàn)象

E程序B：規(guī)定的試驗(yàn)溫度和試驗(yàn)結(jié)果

試樣規(guī)格：

試樣的長(zhǎng)度為（20.5?0.5）MM，寬度為（6.0?0.5）MM，厚度為（2.0?0.2）MM.

沖擊器

沖擊器頭部形狀和尺寸，沖擊器的質(zhì)量為（200?20）g,其工作行程為（40?1）mm。沖擊裝置的彈簧在壓縮狀態(tài)下，沖擊器端部到試樣的距離為（25?1）mm。

低溫測(cè)溫計(jì)

采用最小分度不大于1度的低溫測(cè)溫計(jì)測(cè)量冷凍介質(zhì)的溫度，可使用低溫溫度計(jì)、熱電偶、電阻溫度計(jì)等。低溫溫度計(jì)為內(nèi)標(biāo)式半浸的，以尾長(zhǎng)150MM，浸入液體深度75MM為宜。

組成

設(shè)備由工作臺(tái)、升降夾持器、沖擊裝置、低溫測(cè)溫計(jì)、盛裝冷凍介質(zhì)的低溫容器、攪拌器等部分組成。

升降夾持器

升降夾持器由夾持器和升降裝置組成

從試樣受沖擊部位，到夾持器下端的距離為（11.0加或等于0.5）mm。

沖擊裝置

沖擊裝置由沖擊器和沖擊彈簧等組成。

試樣要求：

試驗(yàn)前，試樣應(yīng)放置在標(biāo)準(zhǔn)實(shí)驗(yàn)室溫度下調(diào)節(jié)至少3H，并在明亮的光線下彎曲試樣并檢查試樣表面，試樣表面應(yīng)光滑，無(wú)雜質(zhì)、損傷及微孔。成品應(yīng)經(jīng)打磨后裁制成相應(yīng)尺寸。

試驗(yàn)結(jié)果與處理

程序A

1、試樣出現(xiàn)破壞的最高溫度，就是該試樣的脆性溫度。

2、溫度值應(yīng)精確到1度。

程序B

如果一組試樣中沒(méi)有任何1個(gè)試樣破壞，則試驗(yàn)結(jié)果為無(wú)破壞。如果一組試樣中有2個(gè)或2個(gè)以上試樣發(fā)生破壞，則試驗(yàn)結(jié)果為破壞。如果一組試樣中只有一個(gè)試樣發(fā)生破壞，則再次取3個(gè)新的完好試樣測(cè)試，3個(gè)試樣均未發(fā)生破壞則試驗(yàn)結(jié)果為無(wú)破壞；否則試驗(yàn)結(jié)果為破壞。

 Heat transfer medium

At the experimental temperature, liquids that can maintain flow without any additional impact on the sample can be used as heat transfer media. This type of heat transfer medium usually uses ethanol, in addition to acetone, siloxane, etc.

Test report

Name or number of this standard

Detailed description and source of sample B

The heat transfer medium, refrigerant or other cooling methods used by C

D Program A: Brittle Temperature and Sample Failure Phenomenon

E program B: specified test temperature and test results

Sample specifications:

The length of the sample is (20.5 ? 0.5) mm, the width is (6.0 ? 0.5) mm, and the thickness is (2.0 ? 0.2) mm

Impactor

The shape and size of the impactor head, the mass of the impactor is (200 ? 20) g, and its working stroke is (40 ? 1) mm. The spring of the impact device is compressed, and the distance from the end of the impactor to the specimen is (25 ? 1) mm.



Low temperature thermometer

Low temperature thermometers with a minimum division of no more than 1 degree can be used to measure the temperature of the frozen medium, including low-temperature thermometers, thermocouples, resistance thermometers, etc. The low-temperature thermometer is an internal standard semi immersion type, with a tail length of 150mm and a liquid immersion depth of 75mm.

form

The equipment consists of a workbench, a lifting clamp, an impact device, a low-temperature thermometer, a low-temperature container for holding the freezing medium, a stirrer, and other parts.

 

Lift gripper

The lifting gripper consists of a gripper and a lifting device

The distance from the impact site of the specimen to the lower end of the gripper is (11.0 plus or equal to 0.5) mm.

 

Impact device

The impact device consists of an impactor and an impact spring.

Sample requirements:

Before the experiment, the sample should be placed at a standard laboratory temperature for at least 3 hours and bent under bright light to inspect the surface. The surface of the sample should be smooth, free of impurities, damage, and micropores. The finished product should be polished and cut to the corresponding size.

 

Experimental results and processing

Program A

1. The highest temperature at which the sample fails is the brittle temperature of the sample.

2. The temperature value should be accurate to 1 degree.

Program B

If none of the samples in a group are damaged, the test result is considered undamaged. If two or more samples in a group fail, the test result is considered as failure. If only one specimen in a group is damaged, three new intact specimens shall be taken for testing. If none of the three specimens are damaged, the test result shall be considered as no damage; Otherwise, the test result will be destructive.