材料硬度检测入门级培训英文资料.ppt

,Hardness Training-Basics Methods,application,products,Erhard Reimann,Zwick GmbH&Co.KGHardness training at SDL Shanghai,May 2005,2,Basics,standards,methods,related productsIntroduction into hardness test methods,(dis-)advantages&applications1.1 Definition of Hardness1.2 Hardness Testing of MetalsRockwell,Vickers,Knoop,Brinell,Martens hardness(universal hardness testing)1.3 Hardness Testing of Plastics and RubberBall indentation,Shore,IRHD,Rockwell,3,Terminology definition:“Hardness is the resistance that a body offers to indentation by another(hard)body”.Martens,1900The technical hardness is a mechanical quantity for describing a material or the state of a material.The hardness cannot be measured directly,it must be derived from primary measurement quantities(e.g.test load,indentation depth,indentation area).Hardness values can only be compared if they have been determined via the same test method with identical test parameters.,4,An explicit hardness value can only be characterised via the following criteria:definition of the hardness value indentor geometry and material,size and indentation duration at test load,as well as the type of loading,state and surface quality of the specimen.The following is at the forefront for selection of a hardness test method:economy,time for specimen preparation,availability of machines and devices.,5,basics overview,methods,6,Basics,Standards,Methods,related productsIntroduction into hardness test methods,(dis-)advantages&applications1.1 Definition of Hardness1.2 Hardness Testing of MetalsRockwell,Vickers,Knoop,Brinell,Martens hardness(universal hardness testing)1.3 Hardness Testing of Plastics and RubberBall indentation,Shore,IRHD,Rockwell,agenda,7,Mainly methods with static force application are used for metals.The indentor(ball,cone,pyramid)made of steel,hard metal or diamond is pressed into the surface of the specimen which is placed on a hard and fixed base.The test load is applied bumplessly with a defined application time and duration.The indentation is measured after load removal for many test methods.,hardness testing of metals,8,Rockwell-overview,Hardness Testing according Rockwell(HR)depth measurement,DIN EN ISO 6508-1,9,Scales-Rockwell,Scale overview Rockwell hardness,Indenter Pre-Load N Total Load N,10,Anpplication range-Rockwell,Application range,120-Diamond1/16“Ball1/8“Ball120-Diamond1/16“Ball,Hardness range Hardness Indentation depth 1 Unit Calculation of in HV30 Min.Max.Max.Min.Hardness,11,Rockwell application examples,12,Rockwell tips,Tips for Rockwell(HR):1 HR-Unit means 2 or 1m indentation depth no displacement of specimen during testing proper specimen support,no burr no dirt(specimen,diamond)prevent diamond of damage regard correct choice“of scale regard minimum thickness(indentation depth 1/10 or 1/15)no imprint on support surface regard minimum distance(5mm)no shocks,vibrations,strikes,13,Rockwell product overview,Zwick ZHR-Reihe,Zwick ZHU250Zwick ZHU187,5,Zwick ZHU0.2/Z2.5,Zwick ZHU2.5/Z2.5,Zwick 3106,New!,14,Vickers-overview,Hardness Testing according Vickers(HV)optical indentation measurement,DIN EN ISO 6507-1,DIN ISO 4516,15,Vickers tips,Tips for Vickers(HV):no shocks,vibration,strikes contact diamond-specimen without shock use at least polished surfaces take an appropriate magnification minimise meas.errors horizontal specimen support,no dirt(specimen,diamond)prevent diamond of damage take an appropriate load regard minimum thickness(indentation depth 1/10 or 1,5*d)regard minimum distance(3*d)take care of load dependency of Vickers,16,Vickers products,overview,Zwick ZHV1mZwick ZHV2m,Zwick ZHU250Zwick ZHU187,5,Zwick ZHU0.2/Z2.5,Zwick ZHU2.5/Z2.5,Zwick ZHV10 AZwick ZHV10 PC,Zwick products for Vickers hardness testing,New!,New!,Zwick ZHV20/Z2.5Zwick ZHV30/Z2.5,17,Knoop-overview,Hardness Testing according Knoop(HK)optical indentation measurement,ISO 4545,DIN ISO 4516,18,Knoop advantages,advantages:Knoop(HK)suitable for small specimen owing to the high diagonal length ratio of approx.7:1better than Vickers for thin specimen or layers as the indentation is not so deep(by the factor 4)but the diagonal lengths are the samesuitable for brittle materials owing to the low susceptibility to crackingno influence on the functionality of the test surface owing to the shallow test indentations,19,Knoop disadvantages,disadvantages:Knoop(HK)time consuming to achieve a sufficiently fine test area sensitivity of the diamond indentor to damage time consuming alignment of the test surface to achieve symmetrical test indentations,20,Knoop products,overview,Zwick products for Knoop hardness testing,Zwick ZHV1mZwick ZHV2m,Zwick ZHU250,Zwick ZHU2.5/Z2.5 Zwick ZHU0.2/Z2.5,Zwick ZHV10 AZwick ZHV10 PC,New!,New!,Zwick ZHV20/Z2.5Zwick ZHV30/Z2.5,21,Brinell overview,Hardness Testing according Brinell(HB)optical indentation measurement,DIN EN ISO 6506-1,22,185x Object.90 x Objective45x Objective15x Objective,Application range-Brinell,Application range Brinell hardness,23,Brinell tips,Tips for Brinell(HV):no shocks,vibration,strikes contact hard-metall ball-specimen without shock use at least dressed to size surfaces take an appropriate magnification minimise meas.errors horizontal specimen support without specimen move no dirt(specimen,diamond)take the loading degree of 10 or 30 regard minimum thickness(1,33*d)no imprint on support surface regard minimum distance(3*d),24,Brinell product overview,Zwick ZHU250Zwick ZHU187,5,Zwick ZHU0.2/Z2.5,Zwick ZHU2.5/Z2.5,Zwick ZHV10 AZwick ZHV10 PC,New!,Zwick ZHV20/Z2.5Zwick ZHV30/Z2.5,25,Martens overview(I),Hardness Testing according Martens(HM,HU)depth measurement,DIN EN ISO 14577-1,26,Structure of DIN EN ISO 14577,DIN EN ISO 14577(2003-05):Metallic materials-Instrumented indentation test for determination of hardness and other material parametersPart 1:Test procedure Macro(F 2N;h 6 m),Micro,Nano(h 200 nm)Different geometries of indentersPart 2:Verification and calibration of the testing machineDirect&indirect verificationPart 3:Calibration of reference materialsExamples,27,Content of DIN EN ISO 14577-1,DIN EN ISO 14577-Part 1:Test procedureA:Material parameterHM,HMS,HIT,EIT,CIT,RIT,indentation workB:Types of control C1:Compliance of machineC2:Area correction for indenter(h 6 m)D:Diamond indenterE:Influence of surface roughnessF:Theoretical correlation to Vickers hardness,28,Load.-&unload.curves,Evaluation of the loading and unloading curves,Some characteristics:-Wplast,Welast-HM=f(Fmax,hmax)-HMs=f(sqrt(loading c.)-HUplast=f(Fmax,hr)-HMit=f(Fmax,hmin)-.,loading,unloading,29,Martens hardness,Indentation hardness,Material parameter of Martens hardness,HM evaluation,30,Martens 1 Scale,HM-Scale DIN EN ISO 14577,Materials,conventional methods,The instrumented indentation test delivers material-independent comparable hardness numbers.,31,Martens tips,Tips for Martens(HM):no shocks,vibrations,strikes contact diamond-specimen without shock use at least polished surfaces horizontal specimen support,no dirt(specimen diamondt)prevent diamond of damage choose an appropriate load regard minimun distance and-thickness(indent.depth 1/10)indentation depth 20 x mean roughness value ideal area geometry for h 10 m sufficient,32,Martens product overview,Zwick ZHU0.2/Z2.5,Zwick ZHU2.5/Z2.5,Zwick products for Martens hardness testing,33,rebound hardness testing-overview,Hardness Testing to Leeb(HL)rebounddynamic method/measurement of energy,ASTM A 956,34,Rckprallhrteprfung advantages,disadvantage,advantages:rebound hardness testing(Leeb,HL)extremely short test timesautomatic test sequencetests in all positions,e.g.also overhead measurement by using correction factorssimple handlingportable devicedirect display of the hardness valuedisadvantage:test of specimen that are thin or of low mass is problematic,35,Leeb products,overview,Indentec Rebound tester,Zwick DynaPocket,patented,36,Basics,Standards,Methods,related productsIntroduction into hardness test methods,(dis-)advantages&applications1.1 Definition of Hardness1.2 Hardness Testing of MetalsRockwell,Vickers,Knoop,Brinell,Martens hardness(universal hardness testing)1.3 Hardness Testing of Plastics and RubberBall indentation,Shore,IRHD,Rockwell,agenda,37,hardness testing of platics,rubber(I),The hardness of plastics can,in principle,be determined with the methods of the metals hardness testing.However,the hardness test methods ball indentation hardness,Shore A/D hardness as well as IRHD hardness and Rockwell hardness(scale R.K,)have proven to be the preferred methods.The reasons for this are,on the one hand,the quite often strongly pronounced,time dependent material behaviour of polymer materials,and,on the other hand,the low contrast ratio of the plastic indentation to the surface.The applied test methods therefore usually include a measurement of the indentation depth under test load and a defined hold time.,38,hardness testing of platics,rubber(II),39,ball indentation hardness-overview,Hardness Testing according ball indentation(H)depth measurement,DIN EN ISO 2039-1,40,ball indentation hardness advantages,advantages:ball indentation hardness(H)suitable for hardness tests even under rough conditions owing to the relatively large indentations,suitable for testing the hardness of inhomogeneous and/or anisotropi-cal materials suitable for hardness tests on large finished parts simple and robust indentorcapability of being rationalised or automated by the test sequence and evaluation in the sense of online data processing,41,ball indentation hardness disadvantages,disadvantages:ball indentation hardness(H)limitation when testing small specimen owing to necessary distance(s)(10 mm)between the test indentations,as well as the specimen edge limiting the applicational range,especially at low hardness;the least possible hardness to be determined according to test standard is H 49/30=8,5 N/mm(corresponds to,for example,the hardness of soft PVC with approx.25-27%DOP as plasticizer)no calibrated hardness comparison plates are available,42,ball indentation hardness H products,overview,Zwick ZHU250,Zwick ZHU0.2/Z2.5,Zwick ZHU2.5/Z2.5,New!,Zwick ZHU0.2/Z2.5,Zwick ZHU2.5/Z2.5,Zwick 3106,43,Shore overview,Hardness Testing according Shore hardnessdepth measurement,DIN 53505,ASTM D 2240,ISO 868,44,Shore advantages,advantages:Shore method of hardness tests on elastomers used worldwidesmall testers,simple arrangement resulting in low cost devicessimple operationcan be used in a laboratory with a test stand and defined load application pressure,and can also be used on site by pressing the tester vertically onto the specimen by handtests on specimen or components are possible independent of gravity,even“overhead”or on vertical surfacesgood repeatability and compareabilty of the method capability of being rationalised or automated by the test sequence(indentation depth measurement)and evaluation in the sense of online data processing,45,Shore disadvantages,disadvantages:Shore tests on small parts such as O-rings are not possible fractured surfaces lead to greater test data scatter specimen of thickness 2 mm cannot be tested according to standard no calibrated hardness comparison plates are available testing without a test stand is relatively unexact,46,Shore products,overview,Zwick Shore+test stand,Zwick products for Shore hardness testing,Zwick 311xShore,analogue,Zwick 3105 Shore/IRHDfully-automated,Zwick Shoredigital,47,IRHD overview,Hardness Testing acc.IRHD(International Rubber Hardness Degree)depth measurement,DIN 53519-2,ISO 48,ASTM D 1415,48,IRHD advantages,advantages:IRHD better reproducible test are achieved on concave or convex surfaces than with Shore A hardness teststhe IRHD micro method can be used for small products or for products with dimensions of thickness or diameter down to 1 mm(e.g.O-rings)indentation depth changes owing to relaxation or creep procedures at the time of test data recording are relatively small,this is caused by the long load application duration as compared to that for Shore A(application duration 3 s),49,Shore disadvantages,disadvantages:IRHD test load generation via weights or low load application may cause vibrations,which in turn cause acceleration to the load application;use a suitable damping system no standardised procedure available for indirect,i.e.including all of the devices components,monitoring of the hardness tester via hardness comparison plates no calibrated hardness comparison plates available for plastics,50,Shore,IRHD application areas,51,IRHD products,overview,Zwick 3103Micro-IRHD,Zwick 3105 Shore/IRHDvollautomatischer Hrteprfer,52,Rockwell(plastics)overview,Hardness Testing according Rockwell(HR)depth measurement,scales:R,L,M,E,K,ASTM D 785,53,Rockwell(plastics)advantages,advantages:Rockwell covers a large material range(hardness range);a greater hardness range can be covered through variants with different ball diameters and test loadssuitable for hardness testing even under unsuitable conditionsdevices for hardness tests on metals can be used in principlethe only standardised“ball indentation”hardness test method that records solely the remaining deformation portion,54,Rockwell(plastics)disadvantages,disadvantages:Rockwell no comparison of test results that have been gained through different scales the methods are little used in comparison to others,55,Rockwell product overview,Zwick ZHR-LKP,Zwick ZHU250,Zwick ZHU2.5/Z2.5,Zwick 3106,New!,