Precision parts processing plant Huiwen brief analysis of what is the surface roughness?

Precision Parts Processing Factory Huiwen Briefly Analyzes What Is Surface Roughness?

Surface Roughness Is Very Important For Most Surfaces Involved In Sliding Contact. This Is Because Factors Such As The Initial Rate Of Wear The Nature Of Its Continuity Are Highly Dependent On This Characteristic. These Surfaces Are Generally Load-Bearing Surfaces Need To Be Marked With Roughness To Ensure Suitability For The Intended Use. Many Parts Require Specific Surface Processing Results In Order To Achieve The Required Functions. For Example, The Body Of An Automobile Before Painting The Journal Bearings On A Crankshaft Camshaft. Next, Huiwen, A Precision Parts Processing Factory Will Take You To Understand What Surface Roughness Is.

01What Is Surface Roughness?

Surface Roughness Refers To The Unevenness Of The Machined Surface With Small Spacing Tiny Peaks Valleys. The Distance (Wave Distance) Between Two Peaks Two Valleys Is Very Small (Less Than 1mm), Which Belongs To The Microscopic Geometric Shape Error.

Specifically Refers To The Height Spacing (S) Of Tiny Peaks Valleys (Z). Generally Classified By S: S < 1mm Is Surface Roughness; 1≤S≤10mm Is Waviness; S>10mm Is F Shape.

02How Is Surface Roughness Formed?

The Formation Of Surface Roughness Is Caused By The Processing Of Workpieces In Precision Parts Processing Plants. The Processing Method, Workpiece Material, Process Are All Factors That Affect Surface Roughness.

For Example: When A Precision Parts Processing Plant Is Performing Electrical Discharge Machining , Discharge Bumps Concave-Convex Spots Appear On The Surface Of The Processed Parts .

Due To Differences In Processing Technology Part Materials, The Microscopic Traces Left On The Surface Of The Processed Parts Also Have Various Differences, Such As (Density, Depth, Shape Changes, Etc.).

03The Influence Of Surface Roughness On Workpiece

Wear Resistance Of Workpiece

Matching Stability

Fatigue Strength

Corrosion Resistance

Sealing

Contact Stiffness

Measurement Accuracy

…

Plating Coating, Thermal Conductivity Contact Resistance, Reflection Ability Radiation Performance, Resistance To Liquid Gas Flow, Current Flow On The Conductor Surface, Etc. Will All Have Varying Degrees Of Influence. Huiwen Zhizao Is A Machining Factory With More Than Ten Years Of CNC Machining Experience . It Has A Full Range Of Equipment, CNC Lathe/Milling/Grinding/Drilling/Machining. Partners With Parts Processing Needs Are Welcome To Call Us For Quotes.

04 Evaluation Basis Of Surface Roughness

① Sampling Length

The Unit Length Of Each Parameter In The Precision Parts Processing Plant, The Sampling Length Is The Length Of A Reference Line For Evaluating The Surface Roughness. Under The ISO1997 Standard, 0.08mm, 0.25mm, 0.8mm, 2.5mm, 8mm Are Generally Used As Reference Lengths.

②Evaluation Length

It Is Composed Of N Reference Lengths. The Surface Roughness Of Each Part Of The Component Surface Cannot Truly Reflect The Real Roughness Parameters On One Reference Length, But N Sampling Lengths Are Needed To Evaluate The Surface Roughness. Under The ISO1997 Standard, The Evaluation Length Is Generally N Equal To 5.

③Baseline

The Baseline Is The Profile Centerline For Evaluating Roughness Parameters. Generally, There Are The Least Squares Centerline The Profile Arithmetic Mean Centerline.

[Least Squares Centerline] Is To Perform Least Squares Calculation On The Points Collected During The Measurement Process.

[Arithmetic Mean Center Line Of Contour] Within The Sampling Length, The Areas Of The Upper Lower Parts Of The Contour Of The Center Line Are Equal.

Theoretically, The Least Squares Midline Is An Ideal Reference Line, But It Is Difficult To Obtain In Practical Machining Applications. Therefore, The Arithmetic Mean Midline Of The Contour Is Generally Used Instead, A Straight Line With An Approximate Position Can Be Used Instead During Measurement.

05How To Obtain Surface Roughness?

The Evaluation Of Surface Roughness Is Becoming More More Important In The Manufacturing Industry. To Study Surface Roughness, You Need To Use A Dedicated Machine, Namely: Surface Roughness Measuring Instrument, Composite Measuring Machine Formtracer Avant Series

1. Comparative Method

It Is Used For On-Site Measurement In Workshops Is Often Used For Measuring Medium Relatively Rough Surfaces. The Method Is To Compare The Measured Surface With A Roughness Sample Marked With A Certain Value To Determine The Roughness Value Of The Measured Surface.

2. Needle Method

The Surface Roughness Is Measured By Slowly Sliding A Diamond Stylus With A Tip Curvature Radius Of About 2 Microns Along The Measured Surface. The Up Down Displacement Of The Diamond Stylus Is Converted Into An Electrical Signal By An Electrical Length Sensor. After Amplification, Filtering, Calculation, The Display Instrument Indicates The Surface Roughness Value, The Recorder Can Also Be Used To Record The Profile Curve Of The Measured Section. Generally, A Measuring Tool That Can Only Display The Surface Roughness Value Is Called A Surface Roughness Measuring Instrument, A Surface Roughness Profiler That Can Record The Surface Profile Curve Is Called A Surface Roughness Profiler. Both Measuring Tools Have Electronic Calculation Circuits Electronic Computers, Which Can Automatically Calculate The Arithmetic Mean Deviation Ra Of The Profile, The Ten-Point Height Rz Of The Micro-Roughness, The Maximum Height Ry Of The Profile Many Other Evaluation Parameters. The Measurement Efficiency Is High It Is Suitable For Measuring The Surface Roughness Of Ra Of 0.025 To 6.3 Microns. Huiwen Zhizao Is A Machining Factory With More Than Ten Years Of CNC Processing Experience. It Has A Full Range Of Equipment, CNC Lathe/Milling/Grinding/Drilling/Processing. Partners With Parts Processing Needs Are Welcome To Call Us For Quotations.

Roughness Measuring Machines Can Achieve Different Functions, Have Different Evaluation Methods, Have Different Costs. Before Selecting A Model, You Can Consult With A Professional Manufacturer Choose The Most Suitable Model According To Your Needs.