~~~~~~~~~~~!!!!!!!Literature Review

Austin, TX, USA). Paper presented at TMS/AIMFFall Meeting, Indianapolis, October 2-5. 1989.

This paper presents the results of work on highspeed sliding contact materials focusing on theextension of the operating regimeof the \Vgraphitematerials for low-voltage, high-speed applications.and on CU·\V speed applications.

PRESENT AND FUTURE DEVELOPMENT OFSOFT MAGENTIC PM MATERIALS ANDAPPLICATIONS

A Kordecki, B Weglinski (Techn. Univ. Wroclaw).Paper presented at the 1989 Powder MetallurgyGroup Meeting. 9-11 October, 1989.Bnwness-on-Windermere,

A description of soft magneticpowder composites,such as sinters, dielectrornagnetics andmagnetodielectrics. and problems associated withtheir applications as magnetic cores of electricalconverters, are presented in this paper.

PRODUCTION OF BARIUM FERRITES BY TilECHEMICALLY ACTIVATED SINTERING ANDTOPOTACTICAL METHODS

S Ozbayraktar, et al (Univ. Withwatersrand. SouthAfrica). Paper presented at the 1989 PowderMetallurgy Group Meeting. 9-11 October 1989.Bowness-on-Wlndermere.

The possibility. of manufacturing anisotropicbarium ferritesby a new method was investigated.The kinetics of the chemically activated sinteringand topolactical behaviour and their effect onmagneticqualities are discussed.

RARE EARTH PERMANENT MAGNETS

JOrmerod (Philips Components Ltd. Southport).Paper presented at the 1989 Powder MetallurgyGroup Meeting. 9-11 October 1989,Bowness-on-windermere.

A review of the PM rare earth permanent magnetmarket.

Hard Materials & Cermets

HIGHPRESSURE SINTERING OF COMPACTBORON NITRIDE MODIFICATIONS

F Kupcik, E Matos, Pokroky Pttiskove Me/alurgie.No 2, 1989. 6·19.

The results of sintering CBN and WBN powders ina high-pressure device are described. Influence ofstarting raw materials. sintering condilions andadditives to the CBN powders was studied. Further.results of sintering the WBN powder are presented.Effect ofsintering parameterson some physicalandchemical characteristics, mechanical strength ofgrainsand phasecomposilionofpolycrystalline BNis examined. Resultsof cutting tests are discussed.

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AlzOJ·COATED CEMEf'oI"TED CARBIDE INSERTS

JHofmann. et al, Pokroky Proskove Metalutgie, No2. 1989. 41-56.

The experimental results presentedsuggestthat thecutting life of AI20rcoated inserts increases withthe total coating thickness. On the base of practicalexamples the application of AIzOrcoated insertsduring the steel turning at the high cutting speedsand during the cast iron turning and milling isdemonstrated.

Refractory Metals

EFFECT OF COLD FORGING ONTHEPROPERTIES OF Cu·WMECHANICALLYALLOYED COMPOSITE MATERIALS

JKaczmar, A Niechajowicz [lnst. MachineBuildingTechn. Wroclaw, Poland). Paper presented at the1989 Powder Metallurgy Group Meeting. 9-11,1989, Bowness-on-Windermere.

The effect of cold forging of Cu·W sintered andhot-worked materials on densily, hardness andelectrical conductivity has been evaluated.

DEVELOPMENT AND CONTROL OFMICROSTRUCTURE IN PM W BY SYNTHESISAND REDUCTION OF WOl GELS

CPersad, et al, (Ctr.forMat.Sci and Eng. The Univ.of Texas. Austin, TX. USA). Paper presented atTMS/AIMF Fall Meeting. Indianapolis. October2-5.1989.

Gels produced fromacidic solutions of metallic Whave been investigated as precursor materials forsubmicron metallic W particles. Temperature andpH control in the gel-producing step leads to thenucleation and controlled growth ofWOl particlesdown to 50 mm size. Gels of stoichiometric andnon-stoichlmetric compositionshavebeen studied.

PROBLEMS OF PM·REFRACfORY ALLOYS INAIRCR1\FTINDUSTRY

J Makl, et al, Pokroky Ptaskove Metolutgie, No 2.1989. 20-40.

PM-technology in refractory materials productionis discussed. Advantages and disadvantagesof thistechnology are considered and possibleapplications in the Czechoslovak aircraft industryare presented.

Superalloys

HIGHTEMPERATURE ALLOYS

J D Whittenberger (NASA Lewis Research Center.Cleveland. Ohio. USA). Paper presented atTMS/AIMF Fall Meeting. Indianapolis. October2-5.1989.

In many ways aerospace applications provide the'ultimate' test for high temperature alloys. Asminimal requirements the materials must becapable of being fabricated and possess (1) goodcreep and environmental resistance at hightemperatures and (2) adequate fracture toughnessand fatiguestrength. AlthoughCoo. Fe-,and Ni-basosuperalloys meet these criteria for existingtechnology, the desire for higher operatingtemperatures to improve efficiency means that anew generationof high temperature materials mustbe developed. Possible systems include metalmatrix composites. monolithyic and compositeintermetallics as well as refractory alloys. Theseapproaches. including advantages and problems.are examined in this paper.

DETERMINATION OF TEXTURE IN ZIRCALOYUSING COMPl.ETE POLE FIGURES

S A Wilson (AD Sandvik Steel. Sweden). Scatid.],Me/alI., 18, 1989. 6-12.

-Inordertobeableto measurethe texturein Zircaloyaccurately.a method involvingboth backreflectionand transmission techniques has been developed.Pole figures and texture parameters were obtainedfromthe (0002) and (1010) planes. It was foundthatthe defocusing correction employed increased theaccuracyof the results considerably.

Miscellaneous

MAKING SPCWORK· UTILISATION OFMODIFIED CONTROL LIMITS

S B Morton (GKN Bound Brook Ltd. Litchfield).Paper presented at 1989 Powder MetallurgyGroupMeeting. 9·11 October, 1989,Bowness-on-\Vindermere.

An overviewpaper on the subject of SPC.

CAN WEPREDICT THESTRUCTURE ANDPERFORMANCE OF NEW MATERIALS?

A P Miodownik(Dept. Mat.Sci. &Eng.•Universityof Surrey. UK). Paper presented at 1989 PowderMetallurgy Group Meeting. 9-11 October. 1989,Bowness-on Windermere.

A review of 'new' material developments.

SIMPLE VERSUS HI·TECH SOLUTION TOQUALITY CONTROL PROBLEMS IN A SMALLPOWDER METALLURGY PLANT

D K Napier (Morganite Special Carbons. London).Paper presented at the 1989 Powder MetallrugyGroup Meeting. 9-11 October, 1989.Bowness-on-\Vindermere.

A discussion of the sophisticated statisticaltechniques that can be applied to helpmanufacturersimprovethe quality of their productthrough an increased knowledge of the unitprocesses required to make that product.

MPR January 1990