Manufacturing Processes Lab – MEM564 / LS2/Ziyadi Rev. 00-2013

UNIVERSITI TEKNOLOGI MARA

FAKULTI KEJURUTERAAN MEKANIKAL

Program : Bachelor of Mechanical Engineering (Hons) Manufacturing (EM221) Bachelor of Engineering (Hons) Mechanical (EM220)

Course : Manufacturing Processes LaboratoryCourse Code : MEM564

LAB SHEET NO: 3

TITLE : Surface Roughness Measurement

OBJECTIVE :

To obtain the value of the roughness of a specimen by the CENTER LINE AVERAGE (CLA) or ROUGHNESS AVERAGE (Ra) method by using a Computerized Roughness Measuring Machine.

SPECIMEN & EQUIPTMENT :

a) Specimen ; piston cylinderb) A computerized Surface Roughness Machinec) Digital Planimeter

THEORY :

A surface can never be perfectly smooth and will always have two components of surface texture namely roughness and waviness as shown in figure 1. they may vary from fine to coarse according to the machine process used.

Manufacturing Processes Lab – MEM564 / LS2/Ziyadi Rev. 00-2013

Figure 1

FIND , DRAW , DEFINE:-Waviness height, Flaw , roughness width ,roughness height, waviness width roughness-width cutoff

A means of measuring surface finish that is normally use by ISO is the CLA method. It measures the average value of the departures of both that are above and below the center line average of the surface through a prescribe sample length L . The Mean results if several sampling lengths taken consecutively will give the actual roughness value of the surface of the component.

CLA = ∑ A / (L x Mv)

Where :-

∑ A = Sum of area above and below the center line L = Sample length (graph) Mv = Vertical Magnification

PROCEDURE ON MACHINING PROCESS :

1) Select a cut off wavelength of 0.8 mm by 8 sections on the machine. Set the machine to a vertical magnification to AUTO and horizontal magnification too 100.

2) Place the component on the auto leveling table at a suitable position such that when pick up head is lowered , its stylus contacts the surface of the specimen.

3) Set the machine ; ready to record the measurement.

4) Obtain the roughness profile graph foor the specimen.

PROCEDURE ON MANUAL PROCESS :

1) Step by step procedure on the manual process.2) Insert pictures , graph and etc.

RESULTS :

1) Compare the computerized results with the manual ; calculate results ; percentage error.2) Tabulate your results.

REPORT :

Each students should submit a standard lab/technical report following the PO (Program Outcome) format. Actual pictures of the machine , process , etc. would definitely make your report writing more impressive.

DISCUSSION :

1) Comment on any variations in results for the measured profile2) What are the possible errors involved?3) What are the necessary precautions?

CONCLUSION :

Manufacturing Processes Lab – MEM564 / LS2/Ziyadi Rev. 00-2013

State the outcome of the results and analysis.