V, kkP (e-il I I ENGINEERING RESEARCH INSTITUTE UNIVERSITY OF MICHIGAN ANN ARBOR REPORT NO. 6 POWER HACKSAW OPERATIONS ON TITANIUM AND ITS ALLOYS BY FRANK SOWA L. V. COLWELL Project M993 U. S. ARMY, ORDNANCE CORPS CONTRACT NO. DA-20-018-ORD-11918 January, 1955

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SUMMARY SHEET I. Engineering Research Institute, University of Michigan, Ann Arbor, Michigan II. U. S. Army, Ordnance Corps. III. Project No. TB4-15 Contract DA-20-018 ORD-11918, RAD No. ORDTB-1-12045. IV. Report No. WAL 401/109-6 V. Priority No. - None VI. Investigation of machinability of titanium-base alloys. VII. Object: The object is to investigate the machinability of commercially pure titanium and three alloys of titanium. VIII. Summary: Power hacksawing tests were run on titanium grades Ti 75A, RC 130B, and Ti 130A. All tests were made with-4 pitch saws on a commercial machine operating at three different speeda. The saw materials represented were tungsten high-speed steel andmolybdenum high-speed steel. All tests were made with 1:20 emulsion of soluble oil in water. IX. Conclusions: (a) Titanium requires abnormally high feeding pressure. (b) Molybdenum HSS blades have better even life. (c) Tool wear is manifested.in a gradual reduction in the feed rate at instant feeding pressure. (d) There is little difficulty from broken teeth and blades in sawing titanium compared to some other metals. ii

TECHNICAL REPORT DISTRIBUTION LIST Copy No. 1 2-3 4 5 6 7 8 9-10 11-12 Contractor Department of the Army Office, Chief of Ordnance The Pentagon Washington 25, D. C. Attn: ORDTB - Res. and Matls. Same. Attn: ORDTA - Ammunition Div. Same. Attn: ORDTR - Artillery Div. Same. Attn: ORDTS - Small Arms Div. Same. Attn: ORDTT - Tank Automotive Same. Attn: ORDTU - Rocket Div. Same. Attn: ORDTX-AR - Executive Library Same. Attn: ORDIX Commanding General Aberdeen Proving Ground Aberdeen, Maryland Attn: ORDTE R. D. and E. Library Commanding General Detroit Arsenal Center Line, Michigan Commanding Officer Frankford Arsenal Bridesburg Station Philadelphia 37, Pa. Commanding Officer Picatinny Arsenal Dover, New Jersey Commanding Officer Redstone Arsenal Huntsville, Alabama Commanding Officer Rock Island Arsenal Rock Island, Illinois 13 14-15 19 iii

Copy No. Contractor 20 Commanding Officer Springfield Armory Springfield, Mass. 21 Commanding Officer Watervliet Arsenal Watervliet, New York 22-23 Central Air Documents Office U. B. Building Dayton 2, Ohio Attn: CADO-D 24-25 Commanding Officer Box CM, Duke Station Durham, North Carolina 26 Chief Bureau of Aeronautics Navy Department Washington 25, D. C. 27 Chief Bureau of Ordnance Navy Department Washington 25, D. C. 28 Chief Bureau of Ships Navy Department Washington 25, D. C. 29 Chief Naval Experimental Station Navy Department Annapolis, Maryland 30 Commanding Officer Naval Proving Ground Dahlgren, Virginia Attn: A. and P. Lab. 31 Director Naval Research Laboratory Anacostia Station Washington, D. C. iv

Copy No. Contractor 32 Chief Office of Naval Research Navy Department Washington, D. C. 33 Commanding General Air Materiel Command Wright-Patterson Air Force Base Dayton 2, Ohio Attn: Production Resources MCPB and Flight Research Lab. 34 Commanding General Air Materiel Command Wright-Patterson Air Force Base Dayton 2, Ohio Attn: Materials Lab., MCREXM 35 Director U. S. Department of Interior Bureau of Mines Washington, D. C. 36 Chief Bureau of Mines Eastern Research Station College Park, Maryland 37 National Advisory Committee for Aeronautics 1500 New Hampshire Avenue Washington, D. C. 38 Office of the Chief of Engineers Department of the Army Washington 25, D. C. Attn: Eng. Res. and Dev. Div. Military Oper. 39 U. S. Atomic Energy Commission Technical Information Service P. 0. Box 62 Oak Ridge, Tennessee Attn: Chief, Library Branch v

Copy No. Contractor 40 District Chief Detroit Ordnance District 574 E. Woodbridge Detroit 31, Michigan 41 Massachusetts Institute of Technology Cambridge, Massachusetts Via: Boston Ordnance District 42 Commanding Officer Watertown Arsenal Watertown 72, Massachusetts Attn: Technical Representative 43-44-45- Commanding Officer 46-47-48- Watertown Arsenal 49-50 Watertown 72, Massachusetts Attn: Laboratory 51 Dr. James E. Bryson Office of Naval Research 844 N. Rush Street Chicago 11, Illinois 52 Ford Motor Company 3000 Schaefer Road Dearborn, Michigan Attn: Mr. R. Lesman Supervisor, Development Section Manufacturing Engineering Department Engine and Foundry Division 53-54 Engineering Research Institute Project File University of Michigan Ann Arbor, Michigan Initial distribution has been made of this report in accordance with the distribution list. Additional distribution without recourse to the Ordnance Office may be made to United States military organizations, and to such of their contractors as they certify to be cleared to receive this report and to need it in the furtherance of a military contract. I vi

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN - POWER HACKSAW OPERATIONS ON TITANIUM AND ITS ALLOYS INTRODUCTION Power hacksawing is not subject to as high a degree of control as most metal cutting operations and thus the effect of variables need to be studied only in a general way since it is difficult to make use of precise quantitative measurements. Proceeding on this basis, the program was set up under the following three headings: 1. To determine the optimum operating conditions for sawing titanium and its alloys on a standard power hacksaw with regard to: a. necessity of coolant, determined by the use of coolant and of no coolant; b. feeding pressure, determined by varying the feed value position; and c. cutting speed, determined by the use of low, medium, and high speeds. 2. To compare the relative effectiveness of sawblade materials: a. tungsten (high speed) and b. molybdenum (high-speed). The feed pressure and cutting rate were kept constant, with only the type of blade material varied. A comparison of the average feed rate vs. the amount of material cut revealed the effectiveness of each blade material. 3. To determine power consumption and forces present on the sawblades during hacksawing operations.

- ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN The forces were obtained by attaching two SR-4 strain gages, one on each side, mounted centrally between the holes and near the top edge of the blade. The gages were attached to a strain analyzer and then to a Brush recorder. The instantaneous feeding rate was obtained by attaching a wire from the movable frame of the saw to a potentiometer. Thus, a feeding movement of the frame would vary the output of the potentiometer, which output was recorded on an Illinois recorder. TEST PROCEDURE A 2 by 4 inch cross-section titanium specimen was locked in the clamping vise on the Standard Pereless power hacksaw so that a 3/16 inch thick section would be cut off. A counter device was mounted on the stationary frame and was actuated by the reciprocating cross head carrying the saw blade. The feeding rate was determined by attaching a counterbalanced wire to the nonreciprocating downfeed portion of the frame. The wire from the frame was attached at the other end to a pulley extending from a potentiometer, which was mounted on top of the stationary hacksaw frame. Another wire was attached to the pulley and carried a counterweight at the other end. Thus a movement of the cross head downward would carry the counterweight up, and when the cross head moved upward the counterweight would maintain a tension on the respective wires. This arrangement served to provide a positive movement of the potentiometer, whose changing resistance in a measuring circuit provided a variable voltage which could be translated into inches of feed. This changing voltage was fed into an Illinois recorder and recorded on a constant-speed chart from which the instantaneous feed rates could be taken. These instantaneous feed rate values were used in computations of the amount of metal removed for the determination of horsepower consumed per cubic inch of metal removed. The countermechanism results were used in the computation of average feed rates in the wear tests. Since the material cut was 2 inches wide and 4 inches deep, the number of strokes from the counter divided into 4 inches would give the average feed rate per stroke for the 8 square inch cross section cut. In the determination of the cutting forces and feeding forces, two SR-4 strain gages were mounted midway between the pin holes, as near the top of the blade as possible, and on opposite sides of each sawblade. The mounting of the gages on opposite sides of the blade was to eliminate air effects of lateral deflection. The bridge circuit consisted of the two gages mounted on the blade, used as opposite active gages, and two gages of a blade not in use. The results were recorded on a Brush recorder after being amplified. A calibration was obtained by inverting the blade and moving a known weight along the blade through the positions to be occupied by the stock to be cut. Thus, the brush deflections were converted into I I 2

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN stress. Because the chart moved at a constant rate, the position of the work at the start and finish of the stroke could be determined on the charts. The stress recorded consisted of a horizontal cutting force and a vertical feeding force. However, by inserting the values of the stress from the Brush charts at the start and finish of a stroke into a formula for the stress at each of the respective positions, the horizontal and vertical forces were obtained. Thus, with the horizontal cutting force known, the horsepower was calculated. When this resultant horsepower was divided by the instantaneous volume of metal being removed, the power consumption per unit of metal removed was obtained. EQUIPMENT AND MATERIAL 1. Machine Peerless Hydracut Power Hacksaw Size: 14 by 14 by 6 inch stroke Speeds: 56, 98, and 140 strokes/min. 2. Blades 21 by 2 by.100 - 4T Hacksaw Baldds (Simonds Saw and Steel) of high-speed molybdenum and high-speed tungsten 3. Coolant Soluble oil in water, 1:20 4. Material Cut: (2 by 4 by 18 inch long bars) (a) Titanium Ti 75A (b) Titanium alloy RC 130B (c) Titanium alloy Ti 150A (d) Hot-rolled SAE 1045 steel 5. Instruments SR 4 Strain Gages, type 3-7, 500 Ohms Strain Gage Amplifier (For feeding pressure) 3

- ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN (a) Brush BL320 Carrier Amplifier (b) Brush Recording Oscillograph Westinghouse D. C. recording voltmeter (For feed rate) SUMMARY OF TEST RESULTS Ti 75A (1) This material could be cut at any of the three available speeds, 56, 98, or 140 strokes per minute. From a wear standpoint, the low speed is best. (2) A coolant must be used; otherwise the material will gall and seize and quickly build up in the space between the sawblade teeth. (3) Varying feed pressure can be used, but the full feed pressure results in greater feed rates without any noticeable increase in blade wear. (4) A molybdenum high-speed blade gave a larger feed rate at the same pressure and did not wear any faster than a tungsten high-speed blade. (5) This material cut faster and caused less wear on the saw blades than either Ti 150A or RC 130B. (6) The power consumption is much less than the power consumed by Ti 150A and RC 130B. (7) The effect of surface scale was not detectable. Ti 150A (1) This material could be cut at the two lower speeds, 56 or 98 strokes per minute. From a wear standpoint, the low speed is better. (2) A coolant is necessary; otherwise the saw blade teeth are dulled at a rapid rate. (3) A high feed pressure is necessary; otherwise the blade rides on the surface of the specimen and does not cut. (4) A molybdenum high-speed blade gave a larger feed rate than a tungsten high-speed blade without any more wear shown. I -a / 4

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN (5) The material cut faster than RC 130B but slower than Ti 75A. (6) Initially, this material consumed more power than Ti 75A and RC 130B, but after 32 square inches of cross section was cut it was intermediate between the other two.* (7) The effect of surface scale on the wearing of saw blade teeth was tremendous. The surface should be free of scale to promote longer blade life. RC 130B (1) This material can be cut only at the slowest speed, 56 strokes per minute. At any higher speed the sawblade skews after a short period of use. (2) A coolant is necessary for sawing to reduce the blade wear obtained on a dry cut. (3) A high feed pressure is necessary; otherwise the blade rides on the surface of the specimen and does not cut. (4) A molybdenum high-speed blade gave a larger feed rate than a tungsten high-speed blade and gave the same rate of wear. (5) The material cut at a slower rate than Ti 75A or RC 130B. (6) Initially the material consumed only as much power as Ti 75A, but quickly built up to a point where it consumed fifteen times the power consumed by Ti 75A. (7) The scale on the surface reduces the blade life through greater wear; however., the variations in blade wear than the presence or absence of surface scale. General Comments When a coolant is used, with heavy feed pressure and a slow cutting speed, the saw blade wears gradually and the usable life depends on how small a feeding rate can be economically tolerated. At increased speeds or when * Based on feed rates at the same feed pressure, since no force data were taken on a blade cutting 52 square inches of cross section of a scale-free Ti 150A alloy. 5

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN no coolant is used, the heavy feed pressure necessary raises the temperature at the contact point of the material and sawblade teeth to a point where chip welding and seizure of material occur. WEAR TESTS In order to ascertain the effectiveness of the blade materials and to obtain a quantitative value of wear in terms of material cut, plots of average feed rate in inches per stroke against the number of square inches of cross section of metal cut were used. A conversion to other units can readily be made; for example, the width of kerf was.125 inch, so that the values of the abscissa divided by 8 yield the cubic inches of metal removed. Because a 6-inch stroke was used with a blade having 4 teeth per inch, the feed rates per tooth can be obtained by dividing the ordinate values by 24. 6

TABLE I SUMMARY OF RESULTS Material Permissible Cut Cutting Speed Influence of Surface Scale Necessity of Coolant * Feed Pressure Required Feed Rate-.001 inch/stroke After 32 sq in. cut Initial Blade Material Molybdenum Tungsten Power Consumption, Hp/cu in./min After 32 Initial Sq in. cut - Ti 75A Low Medium High Negligible Some Tremendous Yes Yes Yes Full Full Full 21 14 14 9 RC 150B Low Ti 150A Low 10 6.5 6.0 35 1.9 2.0 4.5 59 8.5 2.9 SAE 1045 40 - 1.7 1.9 * Varied from 450 to 600 psi depending on cutting resistance. ** The feed rate is the result obtained at a slow cutting speed, with full feed pressure, and a 6-inch stroke *** The power consumption was obtained while using tungsten blades, full feed pressure, slow cutting speed, and a coolant. Power Consumption: The power consumptions of Ti 75A, RC 130B, and SAE 1045 were comparatively the same at initial sawing. However, after 32 square inches of cross section were cut, the blade condition was reflected in the power consumption results, with SAE 1045 showing very little increase, Ti 75A doubling its initial value, and RC 130B increasing its power consumption thirty-fold. Although RC 130B consumed only as much power as Ti 75A at the beginning, it required twelve times as much power per cubic inch of metal removed after 32 square inches of cross section were cut.

TABLE II SUMMARY OF POWER CONSUMPTION CALCULATIONS Stress Recorded, psi Blade Beginning- Feed rate, Metal Material Condition ofi End of Fv, lbs Fc, lbs inches/ Removed Hp Hp/cu in./min Stroke Stroke stroke Cu in./min RC 1501 RC 1301 Ti 75A Ti 75A Ti 150A SAE 104 SAE 104 3 New After 32 sq in. New After 52 sq in. New -5 New After 32 ~5 sq in. (Fc, lbs)(56 13,500 15,500 15,500 15,000 16,500 18,000 18,000 37,500 45,500 40, 500 40, 5oo 40,500 48,000 45,000 45,000 600 500 450 425 525 450 450 450 600 675 860 860 1125 1125.014.0065.021.0115.018.040.035.202.009 3505.167.258.580.508.55.59.76.76.99.99 2.0 59.0 1.9 4.5 2.9 1.7 1.9 6 strokes/min) (- ft/stroke) Hp = 55,000 ft-lbs cu in./min Hp/cu in. min = (length of cut, in.)(feed rate, in.)/(stroke, 56 strokes/min)(width of cut, in.) = (4 in.)(56 strokes/min)(.125 in.)(feed-rate, in./stroke) Hp cu in./min

- ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN DISCUSSION OF WEAR-TEST GRAPHS Graph 1 In the power hacksawing of Ti 75A, the molybdenum high-speed blade removed approximately 30% more metal per cutting stroke than the tungsten high-speed blade and did not show any greater rate of wear. Graph 2 In the power hacksawing of Ti 150A, the molybdenum high-speed blade removed approximately 50-355 more metal per cutting stroke than the tungsten blade in one test (A-A'); the figure was approximately 18% in another test (B-B'). The effect of scale on the Ti 150A specimen was not shown becuase it was so tremendous that the blade was completely worn out after one cut of 8 square inches of cross section with an average feed rate of only.002 inch/stroke. Graph 3 In the power hacksawing of RC 130B, molybdenum high-speed blade removed 10-50% more metal per cutting stroke in test (A-A') and 30-40%o more metal per stroke in another test (C-C'). A large difference in the cutting rates of both blade materials was obtained when different samples of RC 150B were cut. Graph 4 In the power hacksawing of RC 130B with a scaled surface, the molybdenum high-speed blade removed from 6-50% more metal per cutting stroke than the tungsten blade. A comparison of Graph 4 with Graph 3 shows that the RC 130B itself has a greater effect in producing variations in cutting rate than the presence or absence of scale on the surface of the RC 130B. A comparison of Graphs 1, 2, 3, and 4, shows that Ti 75A was cut at the fastest rate, followed by Ti 150A and then RC 150B. I J 9

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN Graph 5 - Graph 6 In the power hacksawing of Ti 75A at various speeds, the molybdenum high-speed blade removes metal at a faster rate than a tungsten blade at the same speed. In addition, Graph 6 shows that the blades' cutting ability is destroyed by gradual wear. Also, the curves indicate a higher feed rate for lower speeds. 10

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN PHOTOGRAPHS OF HACKSAW BLADES AT 5.5 DIAMETER MAGNIFICATION Photo 1 The scale on the Ti 150A alloy broke down the sawblade teeth and caused extremely rapid wear to develop the lands on the teeth as shown here. Photo 2 On a specimen of Ti 150A alloy which had the scale removed by a shaper, the sawblade teeth showed much less wear even though four times as much material had been cut as was cut with the blade in photo 1. Photo 3 On a specimen of RC 130B with the surface scale present, the sawblade teeth showed the same type of wear on edge of the teeth as in photo 2. Photo 4 On a specimen of RC 130B with the surface scale removed, the sawblade showed a slightly lesser wear than in photo 3 but the wear was still on the corners.Photo 5 On a specimen of Ti 75A with the scale removed, the sawblade showed very little wear. Photo 6 On a speciman of RC 130B with the surface scale present, the sawblade skewed badly and was removed. Cutting speed was 98 strokes per minute. 11

ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN STRESS CHARTS FOR HACKSAW TESTS The stress patterns shown on the following charts involve both the horizontal cutting force and the vertical feeding force. The configuration obtained is the result of the shifting of the point of application of the vertical force during a cutting stroke, resulting in a greater bending stress produced near the end of the stroke than at the beginning of the stroke. The analysis of the forces involved during a cutting stroke are shown with equations for the stress recorded at the start and finish of the cutting stroke in terms of horizontal and vertical forces. By inserting the values o stress obtained at the start and finish of the stroke in their respective equations, the horizontal and vertical forces involved in the sawing of the various materials was obtained. 12

Tm~~~~~~~~~~~~~~~~~~~1.:I F..-, ~~~~Ii ~~ ~ -- _ I —: ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ - 4 — -k - t - A - + — - - ----- 1 - - - - - I I I k.. I I I.-I I - I I I - I % I I I I - V- - l - A - - V — -- t —l — ------ -Y - -- --------— _ \ - - X \ X X \ v \ \ X \ \ \. \ \ \ - X \ -\ -\ - -— \ ----\ -- - -= - -— \ ALLOY 150A NEW BLADE NO SCALE 1500 PSI/LINE COMPLETE STROKE ~ 1/4":.-_-7 ' — -:-A-7- " i 1045 STEEL NEW BLADE NO SCALE 1500 PSI/LINE COMPLETE STROKE 5 1/4 "

MATERIAL CALIBRATION 1500 PSI/VERTICAL ULNE COMPLETE STROKE ~ I 1/8 HORIZONTAL. — -.....:.n — -i. - -. / —.- -.!. -I / / WE tf jA,& il\'','\ 4 ~ — I ii '+~~~~~~~~~~~~~~~~~~~~ — "_~~~~~~~~~7 NEW BLADE MATERIAL 304 S8 BROKE AT START OF 4 TH. STROKE.... - -,.q —I r:i.. t - " CI' I I,......,, NEW BLADE MATERIAL 1045 STEEL,(CHART SPEED ACCOUNTS FOR THE HORIZONTAL SPACIiN OF THE RECORD)::: —.".:.- ':-' ' ' ~ '.. i —: i '"-~~~~~~~~~~~....~~~,-Y —,t-t- ~ ' =,-, -. =.-,' k%' ____________I_ — 4- --- - _8 '_ — _ —_ 7 I- -/- /, i. /:,, ~'-...'.............I._-'- -— i Ji —_ —:i —i".....I — -i -,..;: I ---?.. '-:-: '.:-P —+-~:+ —H NEW BLADE MATERIAL 1045 STEEL (CONTINUATION OF ABOVE RECORD AT THE STD. SPEED USED AT OTHER MATERIALS ) It 7- - I- -t- - i., _, -/'i- I — _ ---::I I I -/ ~~~f ~ ~.fi I-.. — /I II - t -1 -t- - _: ~ 1'tz I L. ~ — w 1 -,~' I. II 47 - __t _ _\ 6 z "- "~ -.. ~ - - I - l l a - A 4 4 4 T _ \ _ -_s 1 I --- ~ ~

ALLOY 150A CALIBRATION 7500 PSI/VERTICAL LINE COMPLETE STROKE " I 1/8 " HORIZONTAL / -ff4 - C7-f~:" f j- T7 / 1j -*ik.i:..J~I~t / / I l ~7 ~-:~- I L- I~~~~.t a1. ~. BLADE NO 19 (AFTER CUTTING 32 SQ. IN. CROSS SECTION) SCALE ON ALLOY X 1/5,...-~- -=+... —_ t.....i..1 ' -= - i...: — 4 -".. ----":. =4=~~~~~~~~~~ @ti.t — rp-~-:i-C1 -i ~ -- I- - -- -— X-t = --— 1:7__!._ 39 \ BLADE NO. 19 (AFTER CUTTING 32 SQ. IN. CROSS SECTION) SCALE ON ALLOY X 100

ALLOY 150 A CALIBRATION 1500 PSI/VERTICAL LINE COMPLETE STROKE * I 1/16 HORIZONTAL it'-V \ \\ r-wA1 rr tt _: —4:::-._ _...._.."-::. s_...- W t- - -t_____ _~~~ ~ ~.4.j - -- - — i=- 2 t::":- ':': '"- '-'/:- I,'I, i i J ====================== = ======:== > -r t:' —_,' —L::............~.........: ':: J ~ T t -- i.......-,! ---"T' —F — z —,- -::: -:'.- ":l::'.-"-:-:':'' ' f" I! i' ~ '.__t-.~:.......t It:j..f_~l~-.....~~.......... 4...................:..:. ' I I I' ~ ', ~ i i _-~!~~~~~:::...t —,!:tI!'......~.:..... l:.....im ', _ _ '.. _. -, -.., --- NEW BLADE NO SCALE ON ALLOY Ii hi t~~~~~~../.:- '- / - " i ' —. ~:'.'.-"~~..,,_-/',.,4__ t.>_;.'._/j_."ZL......'_.!<.:,+':._;._;:: —::::-:f- J-:-, -.: ~,,/! J! ': r ~~~~~ ~~~~~-: — --.... _1_,_,.......,!"t:....:-.1:Ji t: ': ' '1 'i ": —'! — - —. \- ' - ~~~~:........_...:.__L:,__, _L J:.....~'-4-__............,__~.._,_.._: rHi L. _L3c^i 7, F --- —.-,-J.::V-V^ ' -:, ^-7............... ',! X?{ S,'_ NEW BLADE SCALE ON ALLOY BLADE NO. 19 (AFTER CUTTING 32 SQ. IN. CROSS SECTION) SCALE ON ALLOY II _- I; - r l ' / ~ ' I, ' I -/._-' — I t - * -I _- -. II_-. - i - -... I --- - I. -. - -. - - - I -— ]. - i - I -- I 1, e -tv - 1 i - I - of i. -. "- lr I r Ii\\\l\ i " ---A Ir -5~~~-~ 1 —, T A,1

ALLOY 130'B CALIBRATION 1500 PSI/VERTICAL UNE COMPLETE STROKE * I I/" HORIZONTAL NEW BLADE NO SCALE ON ALLOY I. -\ ---. * * \:A yv-7 9 — I I-t-:o —4 -- U._ KI_ BLADE NO.20 (AFTER CUTTING 32 SQ. IN. CROSS SECTION) NO SCALE ON ALLOY NEW BLADE SCALE ON ALLOY BLADE NO. 20 (AFTER CUTTING 32 S. IN. CROSS SECTION) SCALE ON ALLOY ~ I — I II I I

CAL BR4 MATERIAL 75A 1500 P COMPLE )09 THE BRUSH DEVELOPM.Nt CO. ATION '81/VERTICAL LINE ETE STROKE ~ I 1/16 HORIZONTAL BL S -1 — PR i — "f-z' JaB It 777/:f — NEW BLADE J D — 8i NO SCALE ON METAL Ii.. I IJ -. — LL I - J - " I -- i — M - - --..- I.-. - ---- - -— i vc -w4- v' tf I z \ ~ \ I 7i~ ~ I - -1~ ~ w -z \K7 Kf\3 1\ \ I I — r ----4 —: —:1:: t:.- - — ~ --- ---- -. — - - ART I BLADE (AFTER CUTTING 32 SQ. IN. CROSS SECTION) NO SCALE ON METAL f --- - - f — - -. ---: -4..T I J 1-. L 7 1 + I- __ -~~ ---- I_-tI i I -" - - -t-V =-I i 7~7A 1-4 f:: Af-l:I 't,..... -1-'-. --- T — I.. i - 11. I - - 1 - i t is I -.. -T —'T T- -- I '... —, 7777 I - -- I I I I I I -1 - i - - IA — l - — ' f77jA7+.7 hA \L+\i4 99Q\hij: \rK\WVI: \+i\WiA5 E BRUSH DEVELOPMENT CO. - PRINTED IN US.A. BS-CAL- NEW BLADE IA-_ - 7- 7 --- SCALE ON METAL I *= I I A.m -^f _ ^a:__

L- X L-X 5. — I ---- L/2 I I -I I J SR-4 GAGE i I~~~~~ h/2 4 I rX -S I -2~ - - L/2- X~~~~~~ Bending Stress at SR-4 Gage - M T where M = F L - x ( L M = F c c + Fv L 2V ( 2x I bh3 (.l)(8) 12 = 12 = 0.067 Fv - vertical force on blade Fc - horizontal cutting force X - distance of Fv from pin hole h - height of blade, 2 inches b - thickness of blade, 0.100 inch L - length of blade, 21 inches Strain gage located at midpoint at top edge c - distance of strain gage from neutral axis, 1 inch Mc Fc S - total stress at gage = I-b-h At beginning of stroke x = 2 inches At end of 6" stroke x = 8 inches SB = 15 Fv + 10 Fc SE = 60 Fv + 10 Fc By using the values of SB and SE, obtained from the Brush charts, the values of Fv and Fc are computed.

56 STROKES/MIN. FULL FEED PRESSURE AFTER 32 SQ. IN. CUT MAO. X 5.5 CLEANED SURFACE FIG.4 98 STROKES /MIN. FULL FEED PRESSURE AFTER 32 SQ. IN. CUT CLEANED SURFACE FIG.5 OXIDIZED SURFACE (ONLY 2 SQ. IN. CROSS SECTION CUT ) FIG. 6

56 STROKES/MIN. FULL FEED PRESSURE AFTER 32 SQ. IN. CUT MAG. X 5.5 FIG. I OXIDIZED SURFACE (ONLY 8 SQ. IN. CROSS SECTION CUT ) CLEANED SURFACE FI6.2 OXIDIZED SURFACE FIG. 3

0 Lo tin. sm 0 0 0 0 -I. 0 0 -Q) graph no.6 I I___ ______ __ __ ___ effect of varying strokes per 18 minute of full feed pressure |17 U\_II_ I I___ ___ 1__ 1on blade life for cutting Ti-75A, molybdenum Hi-speed 16 \ \ _ ___ _________ ___blades. 14:13 14__ ___ ___ _ __ _56 strokes per minute 713 ______ ______ ______ __98 strokes per minute 10. _ _ ^ F^ c^ a ^^A An __n a _ ^ f ^ A 110!5 Ir^ I I t1o 0 i _ IA _ O 1tC Z.n 8 16 24 32,u cm 0~ n4 uz oo u ioo n o vl t number of square inches cut lie u e. 0 41 lc.IO

GRAPH 5 EFFECT OF VARYING STROKE/MIN. AT FULL PRESSURE ON BLADE LIFE FOR CUTTING TI-75A O-N -tf _ TUNGSTEN HI-SPEED BLADES A Z% 15 -[ < - - __ ___4 __ __ _ 56 strokes per minute 0 l12 ~f- II- - - -98 strokes per minute Q t -S I - - -- 1-"40s strokes per minute 0 0J6,, I p 0 e8, J e o 24. u32 number of square inces of cross section cut

20 19 18 17 16 15 14 rJ 0 Iwt Im a 0 0 d LLU. Ld CD 0: 13 12 II 10 9 8 7 6 5 4 3 2 0 I0 - I- - I - -I 1% B I I w I N*N I I I I I I I 11 I I I I - GRAPH NO.4 B- MOLYBDENUM BLADE B'- TUNGSTEN BLADE MATERIAL 130 B CONDITION: SCALE ON SURFACE 56 STROKES/ MINUTE FULL FEED PRESSURE COOLANT ' SOLUBLE OIL AND WATER 20: 1 i i i m m m * - I-Im m I m I I I m~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I 0 8 16 24 32 40 48 56 NUMBER OF SQUARE INCHES OF CROSS SECTION CUT

a ^ eCU 19 18 17 16 15 14 0 - U) 0 0 ICO 0 IL. LU U4 13 12 II 10 9 8 7 6 5 4 3 2 0 IV II I _ _ _ __ _.. _ __ _ _ _ C A' I ^.ZC'Z GRAPH NO. 3 C- A - MOLYBDENUM BLADE C'-A'- TUNGSTEN BLADE MATERIAL, 130 B CONDITION: NO SCALE ON SURFACE 56 STROKES / MINUTE FULL FEED PRESSURE COOLANT: SOLUBLE OIL AND WATER 20 I 0 8 16 24 32 40 48 56 NUMBER OF SQUARE INCHES OF CROSS SECTION CUT

19 18 17 16 15 14 13 12 II 10 9 8 GRAPH NO. 2 A-B MOLYBDENUM BLADES A'-B' TUNGSTEN BLADES MATERIAL 150 A CONDITION NO SCALE ON SURFACE 56 STROKES/ MINUTE FULL FEED PRESSURE COOLANT: SOLUBLE OIL AND WATER 20: 0 en Ia 0 0 LJ w LU CL LL at w U. w <[ 7 6 5 4 3 2 I 0 0 8 16 24 32 40 48 56 NUMBER OF SQUARE INCHES OF CROSS SECTION CUT

UNIVERSITY OF M I CHi GAN 3 9015 02841 28 I 20 19 18 17 16 15 14 LL3 I — -all o 11 0 d 10 0 T EEMMFq 1 a I T GRAPH NO. I _A.-\ -11 _ X I A-MOLYBDENUM 'BLADE B-TUNGSTEN BLADE MATERIAL 75 A CONDITIONtSCALE ON SURFACE 56 STROKES / M I N. FULL FEED PRESSURE COOLANT:SOLUBLE OIL AND WATER 20:1 I i F i \h, _St w Lr 0 LL w Lw 4 9 8 7 6 5 4 3 2 0 I I 'ILS I NOf --...~~~~~~~~~~~~~~,qq** 'NB -= --- —------— X. I X T TTT, I I I GILII~~~~~~~~~~~~~~, 0 8 16 24 32 40 48 56 NUMBER OF SQUARE INCHES OF CROSS SECTION CUT