فحص تأثير الأمبير و سرعة القطع علي عرض القطع باستخدام التشغيل بقوس البلازما لضبط جودة قطع الأسطح المعدنية من ال Al سمك 10 مم

الملخص EN

This study aims to investigate the effect of ampere and cutting speed on kerf width (KW) in order to optimize cutting quality of 10 mm Aluminum (Al) surfaces using Plasma Arc Machining (PAM).

PAM is an alternative, fast, cheap and technique compared to other techniques like Laser Beam Machining and Abrasive Water Jet Machining.

Ampere and cutting speed values are considered to obtain the influence of these parameters on cutting quality .

The experimental approach is used to operate 27 specimens through cutting.

They are divided into three groups.

Different Cutting speeds and 9 different ampere values were used to every group.

Cutting path design included straight line, acute angles, square angles, obtuse angles, and curved line.

KW measurements were investigated, recorded and evaluated.

All specimens results were compared, discussed and represented graphically in order to determine the values of parameters we must use to get the optimum cutting quality.

The following are the major results.

Some of the recorded values allowed for lower KW using medium amps and cutting speeds and led to higher cutting quality.

Also, the use of high cutting speeds at the starting point of cutting KW (key hole) led to minimum cutting width, but the increase in amps had the greatest effect and increased the KW.

Also, using fewer amps at the straight line of the cutting path resulted in a lower KW.

When increasing the cutting speed, the KW became at the minimal.

As for using higher ampere that produce a KW at the maximum sampling level and to obtain appropriate cutting quality, this requires the use of higher cutting speeds with fewer amps to allow a KW at the minimum.

This turns out that the relationship is direct between each of the amps and the width of the cut.

This means that the more the amps, the more the kerf width; and the less the amps, the kerf width, hence the cut quality .

As the KW decreased through using fewer amps at the right angle, the KW increased with the increase in amps at the same cutting speeds used for the right angle and in the middle of the curve along the cutting path.

In addition, the KW quality at the obtuse and the right angles was significantly lower than the KW quality in the case of the acute angle and the angle that corresponds to the diagonal line with the curve.

But, when reducing the ampere, the KW decreased and the cutting quality increased.

On the other hand, the cutting was bad at the acute angle and at the angle that corresponds to the diagonal line with the curve, so it should be avoided when designing the cutting path with a plasma arc .

Also, using high cutting speeds at acute angle with fewer amps produced lower KW and higher quality.

Even all the cutting speeds and amps used at the acute angle produced a KW at the maximum, contrary to the cut at the right angle where the cut width was lower and at the minimum.

In addition, the use of a lower speed and a lower ampere allowed a lower cut width at the end of the curve of the cutting path.

It turned out that the relationship is inversely between the cutting speed and the KW.

The higher the speed, the lower the KW and the higher the cutting quality, the lower the cutting speed, the greater the cutting width and the lower the cutting quality.

Also, the thickness of 10 mm Al prevented melting of the cutting edges during operating and the higher thickness helped to keep the Heat Input to work, differently from thin thicknesses.

The difficulty of controlling the cutting of thin thicknesses of Al was also shown because the surface retains the heat generated from operating and melting.

The lowest reading was 2,217 mm at the right angle as a result of using the 190 ampere values with the cutting speed of 1100 mm /min, arc voltage 130 volt and gass pressure 4.2 bar.

This is the optimum value to obtain the minimum KW and higher cutting quality