Cutting tool of pottery and porcelain does the experiment of steel of milling extra high strength to consider

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The research of technology of cutting of material of 1 foreword difficult treatment has important sense on theory and practice. The research target of this project is steel of some brand extra high strength, this steel is planted content of element of material Ni, Cr, Mo is higher, have tall hardness (> 45HRC) , high strenth (bending strength 1174MPa) and good tenacity, it is because of its exceedingly good physics, mechanical function important to having on national defence industry application. The social estate of overall treatment property that this steel plants is 8 class, belong to typical difficult treatment material, at present cutting tool of main use hard alloy undertakes cutting is machined, but cutting tool wears away, damaged is serious, treatment efficiency is low, finished cost is high, restricted manufacturing success badly. This research uses Al2O3 respectively base, Al2O3-Ti(NC) base with Si3N4-Al2O3 base cutting tool of 3 kinds of pottery and porcelain undertook to steel of this brand extra high strength milling machines an experiment working, through studying its cutting performance, discuss the effective cutting tool that suits to process this data and technique. 2 experiments condition and material of test specimen of methodological test condition: Steel of some brand extra high strength, 60mm of × of 60mm of × of 160mm of test specimen dimension. Experiment cutting tool: Razor blade of YT15 hard alloy, al2O3 base, Al2O3-Ti (NC) radical and Si3N4-Al2O3 base cutting tool of pottery and porcelain. The composition of cutting tool of 3 kinds of pottery and porcelain and sexual visibility are expressed 1. Express brand of cutting tool of 1 pottery and porcelain and hardness of series of composition of function experiment cutting tool (HRA) bending strength (1 Si3N4+Al2O3+TiC Si3N4-Al2O3 of cutting tool of MPa) pottery and porcelain base 2 Al2O3+Ti(NC) Al2O3-Ti(NC) of cutting tool of 94 850 pottery and porcelain base 94.

3 Al2O3+TiC Al2O3 of cutting tool of 5 850 pottery and porcelain base 93.

030 cutting tool of 5 880 ～ geometrical parameter: G0=0 ° , a0=0 ° , 15 ° of × of Br1 × G01=1mm, re=2.

5mm. Cutting means: Semmetry of odd tine end panel does milling. Mill bit body: D=125mm, gp=-9 ° , gr=-3 ° . Machine tool: Milling machine of XS5040 vertical lifting platform. Measurement unit: Small-sized tool microscope, kistler3 measures power instrument to piezocrystal, measuring instrument of exterior surface roughness. Method of experiment of cutting tool durability is in feed F=0.

1mm/r, cutting deepness Ap=1mm, cutting speed is the cutting condition of V=123, 157m/min to fall respectively, undertake to cutting tool of 3 kinds of pottery and porcelain cutting tool durability experiments respectively, draw gives cutting tool wear curve, establish T-V experience formula. Method of milling force experiment is in feed F=0.

1mm/r, cutting deepness Ap=1mm, cutting speed is V=123 respectively, 157, 196, below the cutting condition of 247m/min, mix to cutting tool of YT15 hard alloy respectively cutting tool of pottery and porcelain 1 undertake cutting force experiments, draw goes out advocate cutting force curve, establish Fz-V experience formula. Method of experiment of treatment surface surface roughness falls in the condition of cutting speed V=123, 157m/min, undertake with cutting tool of 3 kinds of pottery and porcelain cutting experiments respectively, measure, the exterior surface roughness that the record already processed work is worth. The impact of 3 tests result and analytic cutting condition to cutting tool durability experiments originally in, in identical cutting dosage (V=123, 157m/min, ap=1mm, f=0.

Of the cutting tool of 3 kinds of pottery and porcelain that gets below 1mm/r) hind wear curve is like knife face the graph is shown 1 times. (A)V=123 M/min (b)V=157 M/min pursues of cutting tool of 3 kinds of 1 pottery and porcelain hind knife face wear curve is seen by the graph, cutting tool of pottery and porcelain - in wear away normally of level wear away more acuteness, achieved cutting tool to grind blunt standard inside very short time; Cutting tool of pottery and porcelain 1, the wearability of 3 is better, wear away normally in cutting tool of level wear away slower, even, compare with the posture of adopts generally cutting tool of YT15 hard alloy in be being produced at present, cutting tool durability has relatively rise substantially. Cutting tool of pottery and porcelain 2 wear away below condition of speed of two kinds of cutting all more serious consideration is cutting temperature taller, the Ni in workpiece material diffuses to cutting tool center, make hardness of cutting tool surface drops, cutting tool material and workpiece material endophilicity increase, felt wears away to increase subsequently, bring about cutting tool durability to reduce. The durability of 3 is in cutting tool of pottery and porcelain when V=157 M/min relatively drop apparently when V=123 M/min, because,this is of the cutting tool when V=123 M/min basically wear away the mechanism wears away for abrasive and felt wears away, cutting tool wears away slower, durability is consequently taller; When V=157 M/min, lift as cutting temperature, diffuse the place in wearing away in cutting tool occupies specific gravity to rise, make function of cutting tool material is reduced, cutting tool wears away aggravate. Cutting tool of pottery and porcelain the durability of 1 is highest (36min) , because the Si3N4 in cutting tool material and TiC are oxidized in cutting process,this is, oxide of Si, Ti was contained to have solid lubricant effect in what attrition surface generates, can reduce the attrition force between face of the knife after cutting tool and workpiece significantly, the felt that reduced cutting tool thereby wears away, raised cutting tool wearability. Undertake to test data linear returns to an analysis, can reach cutting tool of 3 kinds of pottery and porcelain is in F=0.

The T-V experience formula of steel of extra high strength of the milling below dosage of cutting of 1mm/r, Ap=1mm is cutting tool of pottery and porcelain respectively 1: T=8.

103 × of 492 × V-1.

048r=-0.

Cutting tool of 885 pottery and porcelain 2: T=2.

102 × of 919 × V-0.

710r=-0.

Cutting tool of 842 pottery and porcelain 3: T=8.

107 × of 578 × V-3.

065r=-0.

In 927 type, t is durability, r is correlation coefficient, express T and V between the close degree of correlativity. Afore-mentioned experience formula reflected the concern between the durability of cutting tool of 3 kinds of pottery and porcelain and cutting speed, the choice of speed of the cutting in experimenting for sequel provided important basis. Cutting condition experiments originally to the influence of cutting force in, in identical cutting dosage (V=123, 157, 196, 247m/min, f=1.

1mm/r, the cutting tool of YT15 hard alloy that gets below Ap=1mm) and cutting tool of pottery and porcelain of 1 advocate cutting force curve is shown 2 times like the graph. Cutting tool of graph 2 YT15, pottery and porcelain of 1 advocate cutting force curve by the graph knowable: ① is experimenting cutting speed limits (inside V=123~247m/min) , cutting tool of YT15 hard alloy and cutting tool of pottery and porcelain of 1 advocate cutting force Fz follows cutting rate rise and slow reduce, this makes clear when cutting speed is inferior, of cutting speed rise can bring about cutting force to drop; ② and photograph of razor blade of YT15 hard alloy are compared, cutting tool of pottery and porcelain of 1 advocate cutting force is lesser, because be had when dry cutting of cutting tool of pottery and porcelain,this basically is self-lubricating function, namely the Si3N4 in cutting tool of pottery and porcelain, TiC and Ti(NC) produce oxidation below high temperature, oxide is adherent cutting bits and before between knife face, the average coefficient of friction of face of the knife before can be being reduced, reduced thereby advocate cutting force. Undertake to test data linear returns to an analysis, can reach these two kinds of cutting tool are in F=0.

1mm/r, the Fz-V experience formula of steel of extra high strength of the milling below Ap=1mm cutting dosage is cutting tool of pottery and porcelain respectively 1: Fz=418V-0.

102r=-0.

707YT15 cutting tool: Fz=379V-0.

075r=-0.

In 740 type, fz gives priority to cutting force, r is correlation coefficient, express Fz and V between the close degree of correlativity. Cutting condition experiments originally to machining the influence of exterior surface roughness in, in identical cutting dosage (V=123, 157m/min, ap=1mm, f=0.

The treatment surface surface roughness of the cutting tool of 3 kinds of pottery and porcelain that acquires below 1mm/r) is worth see a table 2. The cutting tool of pottery and porcelain of grade of V(m/min) Ra(µm) of cutting tool of experiment of treatment surface surface roughness that expresses cutting tool of 3 kinds of 2 pottery and porcelain 1 123 0.

480 8 157 0.

2 123 0 of cutting tool of 770 7 pottery and porcelain.

514 8 157 0.

3 123 0 of cutting tool of 486 8 pottery and porcelain.

512 8 157 0.

604 8 by the watch 2 knowable, the value all is in the treatment surface surface roughness of workpiece Ra0.

480 ～ 0.

Between 770µm, this shows with pottery and porcelain cutting tool machines steel of extra high strength to be able to acquire better exterior quality. This is main because: ① uses the means that carry mill as a result of the experiment, by advocate action is excised since cutting blade, and transfer Xiu Guang action reached since blade and deputy cutting blade; Hardness of ② workpiece material tall, tenacity is good, the plasticity in treatment is out of shape bigger, cutting tool and the extruding action that machine the surface rose to machine exterior quality on certain level; Of material of cutting tool of ③ pottery and porcelain self-lubricating performance is better, the coefficient of friction between cutting tool material and workpiece is lesser, the attrition force of the cutting tool in milling process and workpiece is lesser, face of not easy and advanced knife is formed stop layer and the tumour that accumulate bits, because this can acquire better treatment surface quality. Experiment of durability of 4 conclusion cutting tool makes clear: With cutting tool of pottery and porcelain steel of treatment extra high strength can raise cutting tool durability significantly, among them Si3N4-Al2O3 base the cutting function of cutting tool of pottery and porcelain is optimal. Cutting force experiment makes clear: When using cutting tool of pottery and porcelain to process steel of extra high strength advocate cutting force relatively when using cutting tool of YT15 hard alloy, drop somewhat. With cutting tool of pottery and porcelain steel of treatment extra high strength can acquire better exterior quality, treatment surface surface roughness is in Ra0.

480 ～ 0.

Between 770µm. CNC Milling CNC Machining